document_title: Saturn

question_text: what is the length of year on saturn

question_tokens: what is the length of year on saturn

root

text: Saturn

text: Physical characteristics

text: Saturn is a gas giant because it is predominantly composed of hydrogen and helium. It lacks a definite surface, though it may have a solid core.[21] Saturn's rotation causes it to have the shape of an oblate spheroid; that is, it is flattened at the poles and bulges at its equator. Its equatorial and polar radii differ by almost 10%: 60,268 km versus 54,364 km.[5] Jupiter, Uranus, and Neptune, the other giant planets in the Solar System, are also oblate but to a lesser extent. The combination of the bulge and rotation rate means that the effective surface gravity along the equator, 7000896000000000000♠8.96 m/s2, is 74% that at the poles and is lower than the surface gravity of Earth. However, the equatorial escape velocity of nearly 7004360000000000000♠36 km/s is much higher than that for Earth.[22]

tag: p

text: Saturn is the only planet of the Solar System that is less dense than water—about 30% less.[23] Although Saturn's core is considerably denser than water, the average specific density of the planet is 7002690000000000000♠0.69 g/cm3 due to the atmosphere. Jupiter has 318 times Earth's mass,[24] and Saturn is 95 times Earth's mass.[5] Together, Jupiter and Saturn hold 92% of the total planetary mass in the Solar System.[25]

text: Internal structure

text: Despite consisting mostly of hydrogen and helium, most of Saturn's mass is not in the gas phase, because hydrogen becomes a non-ideal liquid when the density is above 7001100000000000000♠0.01 g/cm3, which is reached at a radius containing 99.9% of Saturn's mass. The temperature, pressure, and density inside Saturn all rise steadily toward the core, which causes hydrogen to be a metal in the deeper layers.[25]

text: Standard planetary models suggest that the interior of Saturn is similar to that of Jupiter, having a small rocky core surrounded by hydrogen and helium with trace amounts of various volatiles.[26] This core is similar in composition to Earth, but more dense. Examination of Saturn's gravitational moment, in combination with physical models of the interior, has allowed constraints to be placed on the mass of Saturn's core. In 2004, scientists estimated that the core must be 9–22 times the mass of Earth,[27][28] which corresponds to a diameter of about 25,000 km.[29] This is surrounded by a thicker liquid metallic hydrogen layer, followed by a liquid layer of helium-saturated molecular hydrogen that gradually transitions to a gas with increasing altitude. The outermost layer spans 1,000 km and consists of gas.[30][31][32]

text: Saturn has a hot interior, reaching 11,700 °C at its core, and it radiates 2.5 times more energy into space than it receives from the Sun. Jupiter's thermal energy is generated by the Kelvin–Helmholtz mechanism of slow gravitational compression, but such a process alone may not be sufficient to explain heat production for Saturn, because it is less massive. An alternative or additional mechanism may be generation of heat through the "raining out" of droplets of helium deep in Saturn's interior. As the droplets descend through the lower-density hydrogen, the process releases heat by friction and leaves Saturn's outer layers depleted of helium.[33][34] These descending droplets may have accumulated into a helium shell surrounding the core.[26] Rainfalls of diamonds have been suggested to occur within Saturn, as well as in Jupiter[35] and ice giants Uranus and Neptune.[36]

text: Atmosphere

text: The outer atmosphere of Saturn contains 96.3% molecular hydrogen and 3.25% helium by volume.[37] The proportion of helium is significantly deficient compared to the abundance of this element in the Sun.[26] The quantity of elements heavier than helium (metallicity) is not known precisely, but the proportions are assumed to match the primordial abundances from the formation of the Solar System. The total mass of these heavier elements is estimated to be 19–31 times the mass of the Earth, with a significant fraction located in Saturn's core region.[38]

text: Trace amounts of ammonia, acetylene, ethane, propane, phosphine and methane have been detected in Saturn's atmosphere.[39][40][41] The upper clouds are composed of ammonia crystals, while the lower level clouds appear to consist of either ammonium hydrosulfide (NH4SH) or water.[42] Ultraviolet radiation from the Sun causes methane photolysis in the upper atmosphere, leading to a series of hydrocarbon chemical reactions with the resulting products being carried downward by eddies and diffusion. This photochemical cycle is modulated by Saturn's annual seasonal cycle.[41]

text: Cloud layers

text: Saturn's atmosphere exhibits a banded pattern similar to Jupiter's, but Saturn's bands are much fainter and are much wider near the equator. The nomenclature used to describe these bands is the same as on Jupiter. Saturn's finer cloud patterns were not observed until the flybys of the Voyager spacecraft during the 1980s. Since then, Earth-based telescopy has improved to the point where regular observations can be made.[43]

text: The composition of the clouds varies with depth and increasing pressure. In the upper cloud layers, with the temperature in the range 100–160 K and pressures extending between 0.5–2 bar, the clouds consist of ammonia ice. Water ice clouds begin at a level where the pressure is about 2.5 bar and extend down to 9.5 bar, where temperatures range from 185–270 K. Intermixed in this layer is a band of ammonium hydrosulfide ice, lying in the pressure range 3–6 bar with temperatures of 190–235 K. Finally, the lower layers, where pressures are between 10–20 bar and temperatures are 270–330 K, contains a region of water droplets with ammonia in aqueous solution.[44]

text: Saturn's usually bland atmosphere occasionally exhibits long-lived ovals and other features common on Jupiter. In 1990, the Hubble Space Telescope imaged an enormous white cloud near Saturn's equator that was not present during the Voyager encounters, and in 1994 another smaller storm was observed. The 1990 storm was an example of a Great White Spot, a unique but short-lived phenomenon that occurs once every Saturnian year, roughly every 30 Earth years, around the time of the northern hemisphere's summer solstice.[45] Previous Great White Spots were observed in 1876, 1903, 1933 and 1960, with the 1933 storm being the most famous. If the periodicity is maintained, another storm will occur in about 2020.[46]

text: The winds on Saturn are the second fastest among the Solar System's planets, after Neptune's. Voyager data indicate peak easterly winds of 500 m/s (1,800 km/h).[47] In images from the Cassini spacecraft during 2007, Saturn's northern hemisphere displayed a bright blue hue, similar to Uranus. The color was most likely caused by Rayleigh scattering.[48] Thermography has shown that Saturn's south pole has a warm polar vortex, the only known example of such a phenomenon in the Solar System.[49] Whereas temperatures on Saturn are normally −185 °C, temperatures on the vortex often reach as high as −122 °C, suspected to be the warmest spot on Saturn.[49]

text: North pole hexagonal cloud pattern

text: A persisting hexagonal wave pattern around the north polar vortex in the atmosphere at about 78°N was first noted in the Voyager images.[50][51][52] The sides of the hexagon are each about 13,800 km (8,600 mi) long, which is longer than the diameter of the Earth.[53] The entire structure rotates with a period of 10h 39m 24s (the same period as that of the planet's radio emissions) which is assumed to be equal to the period of rotation of Saturn's interior.[54] The hexagonal feature does not shift in longitude like the other clouds in the visible atmosphere.[55] The pattern's origin is a matter of much speculation. Most scientists think  it is a standing wave pattern in the atmosphere. Polygonal shapes have been replicated in the laboratory through differential rotation of fluids.[56][57]

text: South pole vortex

text: HST imaging of the south polar region indicates the presence of a jet stream, but no strong polar vortex nor any hexagonal standing wave.[58] NASA reported in November 2006 that Cassini had observed a "hurricane-like" storm locked to the south pole that had a clearly defined eyewall.[59][60] Eyewall clouds had not previously been seen on any planet other than Earth. For example, images from the Galileo spacecraft did not show an eyewall in the Great Red Spot of Jupiter.[61]

text: The south pole storm may have been present for billions of years.[62] This vortex is comparable to the size of Earth, and it has winds of 550 km/h.[62]

text: Other features

text: Cassini observed a series of cloud features nicknamed "String of Pearls" found in northern latitudes. These features are cloud clearings that reside in deeper cloud layers.[63]

text: Magnetosphere

text: Saturn has an intrinsic magnetic field that has a simple, symmetric shape – a magnetic dipole. Its strength at the equator – 0.2 gauss (20 µT) – is approximately one twentieth of that of the field around Jupiter and slightly weaker than Earth's magnetic field.[17] As a result, Saturn's magnetosphere is much smaller than Jupiter's.[65] When Voyager 2 entered the magnetosphere, the solar wind pressure was high and the magnetosphere extended only 19 Saturn radii, or 1.1 million km (712,000 mi),[66] although it enlarged within several hours, and remained so for about three days.[67] Most probably, the magnetic field is generated similarly to that of Jupiter – by currents in the liquid metallic-hydrogen layer called a metallic-hydrogen dynamo.[65] This magnetosphere is efficient at deflecting the solar wind particles from the Sun. The moon Titan orbits within the outer part of Saturn's magnetosphere and contributes plasma from the ionized particles in Titan's outer atmosphere.[17] Saturn's magnetosphere, like Earth's, produces aurorae.[68]

text: Orbit and rotation

text: The average distance between Saturn and the Sun is over 1.4 billion kilometers (9 AU). With an average orbital speed of 9.68 km/s,[5] it takes Saturn 10,759 Earth days (or about 29 1⁄2 years)[69] to finish one revolution around the Sun.[5] As a consequence, it forms a near 5:2 mean-motion resonance with Jupiter.[70] The elliptical orbit of Saturn is inclined 2.48° relative to the orbital plane of the Earth.[5] The perihelion and aphelion distances are, respectively, 9.195 and 9.957 AU, on average.[5][71] The visible features on Saturn rotate at different rates depending on latitude and multiple rotation periods have been assigned to various regions (as in Jupiter's case).

text: Astronomers use three different systems for specifying the rotation rate of Saturn. System I has a period of 10 hr 14 min 00 sec (844.3°/d) and encompasses the Equatorial Zone, the South Equatorial Belt and the North Equatorial Belt. The polar regions are considered to have rotation rates similar to System I. All other Saturnian latitudes, excluding the north and south polar regions, are indicated as System II and have been assigned a rotation period of 10 hr 38 min 25.4 sec (810.76°/d). System III refers to Saturn's internal rotation rate. Based on radio emissions from the planet detected by Voyager 1 and Voyager 2,[72] System III has a rotation period of 10 hr 39 min 22.4 sec (810.8°/d). System III has largely superseded System II.[73]

text: A precise value for the rotation period of the interior remains elusive. While approaching Saturn in 2004, Cassini found that the radio rotation period of Saturn had increased appreciably, to approximately 10 hr 45 min 45 sec (± 36 sec).[74][75] The latest estimate of Saturn's rotation (as an indicated rotation rate for Saturn as a whole) based on a compilation of various measurements from the Cassini, Voyager and Pioneer probes was reported in September 2007 is 10 hr 32 min 35 sec.[76]

text: In March 2007, it was found that the variation of radio emissions from the planet did not match Saturn's rotation rate. This variance may be caused by geyser activity on Saturn's moon Enceladus. The water vapor emitted into Saturn's orbit by this activity becomes charged and creates a drag upon Saturn's magnetic field, slowing its rotation slightly relative to the rotation of the planet.[77][78][79]

text: An apparent oddity for Saturn is that it does not have any known trojan asteroids. These are minor planets that orbit the Sun at the stable Lagrangian points, designated L4 and L5, located at 60° angles to the planet along its orbit. Trojan asteroids have been discovered for Mars, Jupiter, Uranus, and Neptune. Orbital resonance mechanisms, including secular resonance, are believed to be the cause of the missing Saturnian trojans.[80]

text: Natural satellites

text: Saturn has 62 known moons, 53 of which have formal names.[81][82] In addition, there is evidence of dozens to hundreds of moonlets with diameters of 40–500 meters in Saturn's rings,[83] which are not considered to be true moons. Titan, the largest moon, comprises more than 90% of the mass in orbit around Saturn, including the rings.[84] Saturn's second-largest moon, Rhea, may have a tenuous ring system of its own,[85] along with a tenuous atmosphere.[86][87][88]

text: Many of the other moons are small: 34 are less than 10 km in diameter and another 14 between 10 and 50 km in diameter.[89] Traditionally, most of Saturn's moons have been named after Titans of Greek mythology. Titan is the only satellite in the Solar System with a major atmosphere,[90][91] in which a complex organic chemistry occurs. It is the only satellite with hydrocarbon lakes.[92][93]

text: On 6 June 2013, scientists at the IAA-CSIC reported the detection of polycyclic aromatic hydrocarbons in the upper atmosphere of Titan, a possible precursor for life.[94] On 23 June 2014, NASA claimed to have strong evidence that nitrogen in the atmosphere of Titan came from materials in the Oort cloud, associated with comets, and not from the materials that formed Saturn in earlier times.[95]

text: Saturn's moon Enceladus, which seems similar in chemical makeup to comets,[96] has often been regarded as a potential habitat for microbial life.[97][98][99][100] Evidence of this possibility includes the satellite's salt-rich particles having an "ocean-like" composition that indicates most of Enceladus's expelled ice comes from the evaporation of liquid salt water.[101][102][103] A 2015 flyby by Cassini through a plume on Enceladus found most of the ingredients to sustain life forms that live by methanogenesis.[104]

text: In April 2014, NASA scientists reported the possible beginning of a new moon within the A Ring, which was imaged by Cassini on 15 April 2013.[105]

text: Planetary rings

text: Saturn is probably best known for the system of planetary rings that makes it visually unique.[31] The rings extend from 6,630 to 120,700 kilometers (4,120 to 75,000 mi) outward from Saturn's equator and average approximately 20 meters (66 ft) in thickness. They are composed predominantly of water ice with trace amounts of tholin impurities, and a peppered coating of approximately 7% amorphous carbon.[106] The particles that make up the rings range in size from specks of dust up to 10 m.[107] While the other gas giants also have ring systems, Saturn's is the largest and most visible.

text: There are two main hypotheses regarding the origin of the rings. One hypothesis is that the rings are remnants of a destroyed moon of Saturn. The second hypothesis is that the rings are left over from the original nebular material from which Saturn formed. Some ice in the E ring comes from the moon Enceladus's geysers.[108][109][110][111] The water abundance of the rings vary radially, with the outermost ring A being the most pure in ice water. This abundance variance may be explained by meteor bombardment.[112]

text: Beyond the main rings at a distance of 12 million km from the planet is the sparse Phoebe ring, which is tilted at an angle of 27° to the other rings and, like Phoebe, orbits in retrograde fashion.[113]

text: Some of the moons of Saturn, including Pandora and Prometheus, act as shepherd moons to confine the rings and prevent them from spreading out.[114] Pan and Atlas cause weak, linear density waves in Saturn's rings that have yielded more reliable calculations of their masses.[115]

text: History of observation and exploration

text: The observation and exploration of Saturn can be divided into three main phases. The first era was ancient observations (such as with the naked eye), before the invention of the modern telescopes. Starting in the 17th century, progressively more advanced telescopic observations from Earth have been made. The third phase is visitation by space probes, by either orbiting or flyby. In the 21st century, observations continue from Earth (including Earth-orbiting observatories like the Hubble Space Telescope) and, until its 2017 retirement, from the Cassini orbiter around Saturn.

text: Ancient observations

text: Saturn has been known since prehistoric times[116] and in early recorded history it was a major character in various mythologies. Babylonian astronomers systematically observed and recorded the movements of Saturn.[117] In ancient Roman mythology, the god Saturnus, from which the planet takes its name, was the god of agriculture.[118] The Romans considered Saturnus the equivalent of the Greek god Cronus.[118] The Greeks had made the outermost planet sacred to Cronus,[119] and the Romans followed suit.  (In modern Greek, the planet retains its ancient name Cronus—Κρόνος: Kronos.)[120]

text: The Greek scientist Ptolemy based his calculations of Saturn's orbit on observations he made while it was in opposition.[121] In Hindu astrology, there are nine astrological objects, known as Navagrahas. Saturn is known as "Shani" and judges everyone based on the good and bad deeds performed in life.[118][121] Ancient Chinese and Japanese culture designated the planet Saturn as the "earth star" (土星). This was based on Five Elements which were traditionally used to classify natural elements.[122][123][124]

text: In ancient Hebrew, Saturn is called 'Shabbathai'.[125] Its angel is Cassiel. Its intelligence or beneficial spirit is 'Agȋȇl (Hebrew: עֲזָאזֵל, translit. ʿAgyal),[126] and its darker spirit (demon) is Zȃzȇl (Hebrew: זאזל, translit. Zazl).[126][127][128] Zazel has been described as a great angel, invoked in Solomonic magic, who is "effective in love conjurations".[129][130] In Ottoman Turkish, Urdu and Malay, the name of Zazel is 'Zuhal', derived from the Arabic language (Arabic: زحل, translit. Zuhal).[127]

text: European observations (17th–19th centuries)

text: Saturn's rings require at least a 15-mm-diameter telescope[131] to resolve and thus were not known to exist until Galileo first saw them in 1610.[132][133] He thought of them as two moons on Saturn's sides.[134][135] It was not until Christiaan Huygens used greater telescopic magnification that this notion was refuted. Huygens discovered Saturn's moon Titan; Giovanni Domenico Cassini later discovered four other moons: Iapetus, Rhea, Tethys and Dione. In 1675, Cassini discovered the gap now known as the Cassini Division.[136]

text: No further discoveries of significance were made until 1789 when William Herschel discovered two further moons, Mimas and Enceladus. The irregularly shaped satellite Hyperion, which has a resonance with Titan, was discovered in 1848 by a British team.[137]

text: In 1899 William Henry Pickering discovered Phoebe, a highly irregular satellite that does not rotate synchronously with Saturn as the larger moons do.[137] Phoebe was the first such satellite found and it takes more than a year to orbit Saturn in a retrograde orbit. During the early 20th century, research on Titan led to the confirmation in 1944 that it had a thick atmosphere – a feature unique among the Solar System's moons.[138]

text: Modern NASA and ESA probes

text: Pioneer 11 flyby

text: Pioneer 11 made the first flyby of Saturn in September 1979, when it passed within 20,000 km of the planet's cloud tops. Images were taken of the planet and a few of its moons, although their resolution was too low to discern surface detail. The spacecraft also studied Saturn's rings, revealing the thin F-ring and the fact that dark gaps in the rings are bright when viewed at high phase angle (towards the Sun), meaning that they contain fine light-scattering material. In addition, Pioneer 11 measured the temperature of Titan.[139]

text: Voyager flybys

text: In November 1980, the Voyager 1 probe visited the Saturn system. It sent back the first high-resolution images of the planet, its rings and satellites. Surface features of various moons were seen for the first time. Voyager 1 performed a close flyby of Titan, increasing knowledge of the atmosphere of the moon. It proved that Titan's atmosphere is impenetrable in visible wavelengths; therefore no surface details were seen. The flyby changed the spacecraft's trajectory out from the plane of the Solar System.[140]

text: Almost a year later, in August 1981, Voyager 2 continued the study of the Saturn system. More close-up images of Saturn's moons were acquired, as well as evidence of changes in the atmosphere and the rings. Unfortunately, during the flyby, the probe's turnable camera platform stuck for a couple of days and some planned imaging was lost. Saturn's gravity was used to direct the spacecraft's trajectory towards Uranus.[140]

text: The probes discovered and confirmed several new satellites orbiting near or within the planet's rings, as well as the small Maxwell Gap (a gap within the C Ring) and Keeler gap (a 42 km wide gap in the A Ring).

text: Cassini–Huygens spacecraft

text: The Cassini–Huygens space probe entered orbit around Saturn on 1 July 2004. In June 2004, it conducted a close flyby of Phoebe, sending back high-resolution images and data. Cassini's flyby of Saturn's largest moon, Titan, captured radar images of large lakes and their coastlines with numerous islands and mountains. The orbiter completed two Titan flybys before releasing the Huygens probe on 25 December 2004. Huygens descended onto the surface of Titan on 14 January 2005.[141]

text: Starting in early 2005, scientists used Cassini to track lightning on Saturn. The power of the lightning is approximately 1,000 times that of lightning on Earth.[142]

text: In 2006, NASA reported that Cassini had found evidence of liquid water reservoirs no more than tens of meters below the surface that erupt in geysers on Saturn's moon Enceladus. These jets of icy particles are emitted into orbit around Saturn from vents in the moon's south polar region.[144] Over 100 geysers have been identified on Enceladus.[143] In May 2011, NASA scientists reported that Enceladus "is emerging as the most habitable spot beyond Earth in the Solar System for life as we know it".[145][146]

text: Cassini photographs have revealed a previously undiscovered planetary ring, outside the brighter main rings of Saturn and inside the G and E rings. The source of this ring is hypothesized to be the crashing of a meteoroid off Janus and Epimetheus.[147] In July 2006, images were returned of hydrocarbon lakes near Titan's north pole, the presence of which were confirmed in January 2007. In March 2007, hydrocarbon seas were found near the North pole, the largest of which is almost the size of the Caspian Sea.[148] In October 2006, the probe detected an 8,000 km diameter cyclone-like storm with an eyewall at Saturn's south pole.[149]

text: From 2004 to 2 November 2009, the probe discovered and confirmed eight new satellites.[150] In April 2013 Cassini sent back images of a hurricane at the planet's north pole 20 times larger than those found on Earth, with winds faster than 530 km/h (330 mph).[151] On 15 September 2017, the Cassini-Huygens spacecraft performed the "Grand Finale" of its mission: a number of passes through gaps between Saturn and Saturn's inner rings.[152][153] The atmospheric entry of Cassini ended the mission.

text: Possible future missions

text: The continued exploration of Saturn is still considered to be a viable option for NASA as part of their ongoing New Frontiers program of missions. NASA previously requested for plans to be put forward for a mission to Saturn that included an atmospheric entry probe and possible investigations into the habitability and possible discovery of life on Saturn's moons Titan and Enceladus.[154]

text: Observation

text: Saturn is the most distant of the five planets easily visible to the naked eye from Earth, the other four being Mercury, Venus, Mars and Jupiter. (Uranus and occasionally 4 Vesta are visible to the naked eye in dark skies.) Saturn appears to the naked eye in the night sky as a bright, yellowish point of light. The mean apparent magnitude  of Saturn is 0.46 with a standard deviation of 0.34[10]. Most of the magnitude variation is due to the inclination of the ring system relative to the Sun and Earth. The brightest magnitude, -0.55, occurs near in time to when the plane of the rings is inclined most highly, and the faintest magnitude, 1.17, occurs around the time when they are least inclined.[10] It takes approximately 29.5 years for the planet to complete an entire circuit of the ecliptic against the background constellations of the zodiac. Most people will require an optical aid (very large binoculars or a small telescope) that magnifies at least 30 times to achieve an image of Saturn's rings, in which clear resolution is present.[31][131]  Twice every Saturnian year (roughly every 15 Earth years), the rings briefly disappear from view, due to the way in which they are angled and because they are so thin. Such a "disappearance" will next occur in 2025, but Saturn will be too close to the Sun for any ring-crossing observation to be possible.[155]

text: Saturn and its rings are best seen when the planet is at, or near, opposition, the configuration of a planet when it is at an elongation of 180°, and thus appears opposite the Sun in the sky. A Saturnian opposition occurs every year—approximately every 378 days—and results in the planet appearing at its brightest. Both the Earth and Saturn orbit the Sun on eccentric orbits, which means their distances from the Sun vary over time, and therefore so do their distances from each other, hence varying the brightness of Saturn from one opposition to the next.  Saturn also appears brighter when the rings are angled such that they are more visible.  For example, during the opposition of 17 December 2002, Saturn appeared at its brightest due to a favorable orientation of its rings relative to the Earth,[156] even though Saturn was closer to the Earth and Sun in late 2003.[156]

text: From time to time Saturn is occulted by the Moon (that is, the Moon covers up Saturn in the sky). As with all the planets in the Solar System, occultations of Saturn occur in "seasons". Saturnian occultations will take place 12 or more times over a 12-month period, followed by about a five-year period in which no such activity is registered.[157] Australian astronomy experts Hill and Horner explain the seasonal nature of Saturnian occultations:

text: This is the result of the fact that the moon’s orbit around the Earth is tilted to the orbit of the Earth around the Sun – and so most of the time, the moon will pass above or below Saturn in the sky, and no occultation will occur. It is only when Saturn lies near the point that the moon’s orbit crosses the "plane of the ecliptic" that occultations can happen – and then they occur every time the moon swings by, until Saturn moves away from the crossing point.[157]

text: Notes

text:
^ Jump up to: a b c d e f g h Refers to the level of 1 bar atmospheric pressure

Jump up ^ Based on the volume within the level of 1 bar atmospheric pressure

tag: ol


document_title: List of The Secret Life of the American Teenager characters

question_text: who plays grant on secret life of the american teenager

text: Main characters[edit]

text: Amy Juergens[edit]

text: Portrayed by Shailene Woodley, Amy gets pregnant after a one-night stand at band camp before her freshman year of high school. At the beginning of the series, she is 15 years old. Upon entering high school, Amy begins a relationship with Ben Boykewich (also 15), a supportive classmate with whom she falls in love. She confesses her pregnancy to her two best friends, Madison and Lauren, who accidentally spread the rumor that Amy had sex with Ricky. During this time, Amy's 13-year-old sister Ashley discovers her pregnancy due to Amy's recent weight gain and erratic behavior, but promises to keep her secret from their parents. Ben proposes to Amy after finding out, because he genuinely loves her, and feels he would be a better father than Ricky due to his family's financial stability. After Amy tells her parents, she contemplates having an abortion, as she is afraid of her peers' perceptions. She changes her mind, but is still adamant about not returning to school. Ricky reaches out to Amy during this time, saying that he wants to be involved with what happens to the baby. Amy plans to go live with her grandmother Mimsy, but is unable to go after discovering that Mimsy is suffering from Alzheimer's disease, and is moving into assisted care living. Amy returns to school, but is uncomfortable with being known as "the pregnant girl".

text: Halfway through her pregnancy, Amy's mother Anne informs her that in order to keep the baby, she will have to find a job and daycare. Anne intends to get a job to replace the loss of her husband George's income as they prepare for divorce. Amy is surprised, since she assumed that her mother would stay home and look after the baby, as she had with her daughters. As a result, Amy and Ben get married using fake IDs, but they learn afterwards that the marriage was void since they were both underage. Amy then decides on adoption, and discovers that her father's longtime employee Donovan and his husband Leon want to adopt the baby. The adoption fails due to Ricky's interference, and she ultimately decides to keep the baby due to the love and support of her family and friends.

text: After Amy decides to keep the baby, Grace and Adrian throw her a baby shower, where Amy then goes into labor. While in the hospital, Amy reprimands Ricky for getting her pregnant, but then realizes that she was equally responsible for what had happened. She gives birth to their son, John, whom she lets Ashley name, and begins to struggle with motherhood.

text: After breaking up with Ben during her sophomore year, Amy briefly dates Jimmy, the son of her mother's ex-boyfriend, but their relationship ends after he finds a condom in her purse. Not knowing this at first, Amy thinks that Jimmy broke up with her because she was a bad kisser, and asks Ricky to kiss her just to be sure. Adrian finds out about the kiss, and sleeps with Ben in order to get back at both of them (however, Adrian believed it was more than a kiss until Ricky informs her after Adrian and Ben's one-night-stand.) Amy and Ben quickly reconcile and get back together around the end of the year.

text: After being accepted into a summer music program in New York, Amy decides to go but is surprised to learn that the program is for teen mothers. During this time, Ben reveals to Amy that Adrian had gotten pregnant from their one-night stand, and that he had been keeping her pregnancy from Amy for several weeks. After breaking up with Ben, she develops feelings for Ricky when he comes to visit. She tells him that if he really wants to be with her, he has to stop sleeping around,and get tested for any sexually transmitted diseases or infections.

text: At the beginning of season four, Amy and Ricky are together and are trying to be a real family for their son. After the stillborn death of Ben and Adrian's daughter, Amy and Ricky begin a sexual relationship. Three months later, Amy moves herself and John into Ricky's little apartment over the butcher shop where he works. Amy decides she wants to marry Ricky, but he thinks she's moving too fast. Later he proposes at their graduation, where he is also valedictorian. At a graduation party, Ricky kisses Adrian one last time; something Amy allowed. The next day, Ricky is surprised that Amy isn't in a hurry to marry, but is content with just being engaged until she feels the time is right for them to marry. Later in the season, Amy thinks she is pregnant again and becomes very moody. Although she finds out that she is not pregnant, she is still irritable. Ricky takes her back to where they first met and Amy begins to become a little more happy and appreciative of Ricky, and more excited about his proposal to her. Shortly after Amy discovers her mother is a lesbian, she tells Ricky that they should just run off and get married, to which Ricky agrees. Amy tells everyone that Ricky and her eloped in the season 5 premiere, keeping the fact they changed their minds at the last minute and are in fact not married a secret. Eventually she breaks off the relationship and goes to college in New York, leaving John with Ricky.

text: Richard "Ricky" Underwood[edit]

text: Portrayed by Daren Kagasoff, Ricky Underwood is the lead male character. His father, Bob, is a drug addict who beat Ricky's mother Nora and sexually abused Ricky as a young child. His mother was both a drug addict and an alcoholic who never helped him out of fear. Ricky was taken away from his parents after the abuse came to light, and put into foster care. As a teenager, Ricky attended Ulysses S. Grant High School, where he was the drummer in the high school marching band and had a reputation of being a promiscuous bad boy. He used to see a therapist, Lauren's father Dr. Ken Fields, who he occasionally visits for advice as an adult. The summer before Ricky's sophomore year, he impregnated Amy Juergens after a one-night stand at band camp, finding out about her pregnancy a few months later. Despite his misgivings over being a good father, Ricky is shown to love and care for his son John. He and Amy go on a date in the fall finale of season 3 and she makes him get tested before considering having sex with him. Ricky tests disease-free, and chooses to not have sex with anyone other than Amy. Their first time having sex occurred in the wake of dealing with the news of Ben and Adrian's stillborn daughter. Amy and John soon move in with Ricky. Amy finds messages left by Adrian, after telling her she's in love with Ricky. Amy gets caught by Ricky, with him stating they should spend some time apart if she can't trust him. Ricky eventually apologizes to Amy and they get back together. Amy tries to get Ricky to propose by doing "wild" things such as giving him a milkshake and a bath. Ricky ends up being the Valedictorian, and at the end of his speech he proposes to Amy. At the graduation party Amy allows Ricky to kiss Adrian one last time to give closure to her. Ricky wants to know when Amy wants to get married, and is taken aback when Amy doesn't seem to be in a hurry to plan their wedding. Amy then has a pregnancy scare, and Ricky is supportive and takes Amy to band camp so she can be happy. Amy told everyone that Ricky and her eloped in the season 5 premiere even though they pulled out at the last minute. Eventually Amy breaks up with him and leaves John in his care while she goes to New York to attend college.

text: Adrian Lee-Boykewich[edit]

text: Portrayed by Francia Raisa, Adrian is the daughter of Ruben Enriquez and Cindy Lee, and the ex-wife of Ben. She is 20 years old. Adrian is both book smart and street smart, hard-edged and emotional. Although she is a straight-A student and a majorette, she has a reputation for being a drama queen and the "school slut". She also has strong feelings for Ricky despite claiming she doesn't anymore since they stopped speaking to each other. Adrian grew up never knowing who her father was, until she went on a search to find him. Her father ended up marrying her mother after 16 years of being apart from each other. Adrian and her parents now live next door to the Juergens family. Her mother is a flight attendant and her father is a District Attorney. Like Ricky, Adrian is also known to use sex to deal with pain. In the episode "Be My, Be My Baby", she reveals that she first had sex when she was fifteen, with her childhood best friend Antonio, who was moving away in order to get cancer treatments. Adrian was infuriated after she found out that Ricky kissed Amy, believing that it went beyond kissing, even though it was a mostly innocent encounter. Adrian had a one-night-stand with Ben in retaliation, and ended up becoming pregnant with his child. She had her mind set on abortion, but she eventually backed out and decided to keep the baby. Adrian's decision to keep the baby received a lot of positive support from her father and even Amy, who had called her to let her know that she was giving Adrian the same offer of a friendship between them that she had given her in the past, because their children might end up becoming friends. Adrian later finds out that she is having a baby girl, which both she and Ben are excited about, and she and Ben later get married. Adrian gives birth to their daughter Mercy, who is tragically stillborn due to heart failure. Adrian and Ben are both absolutely devastated by Mercy's death. After this, Ben realizes he no longer loves Adrian, and that he may never have truly loved her. Ben decides that he wants a divorce. When she finds this out, Adrian tries to get pregnant again, believing that they will fall back in love and be happy again if she has another baby. When this doesn't work, she decides he should leave. After Ben left, Adrian realized she still loved Ricky, so she decided to date a guy named Dante in an attempt to make Ricky jealous. In the process, she meets Dante's brother, Omar, and begins dating him, because Dante left the country without an explanation. But Ricky had other plans - he ended up proposing to Amy at their graduation. Adrian wants one last kiss from Ricky, to see if she still has feelings for him. At the graduation party, she receives the kiss and is happy to discover that the kiss leaves her unmoved; however, Omar is at the party and is offended by Adrian kissing Ricky, and leaves. Disconsolate, Adrian has sex with Henry. The next day, she realizes that she has made a mistake, and repeatedly calls Omar, who does not answer her calls. To her surprise, Dante arrives back from his semester abroad. When she tells him that she has been seeing his brother, he breaks up with her. Adrian and her best friend Grace are fed up with boys, and decide to enroll in summer school together. Shortly after, Adrian gets a letter in the mail, stating that she is legally divorced from Ben. She then completes summer school and shows signs of still being in love with Ricky. She falls back in love with Omar, but denies his proposal of marriage, wanting to wait until her schooling is complete.

text: Benjamin "Ben" Boykewich[edit]

text: Portrayed by Ken Baumann, Benjamin "Ben" Boykewich 15-year-old son of Leo Boykewich, is Amy's high school boyfriend and first love. He meets Amy after his best friend Alice points her out one day at school, and they begin dating and fall in love. He offers to marry Amy when he finds out she's pregnant, but she declined his offer at the time. When Amy's mother Anne, tells her that she must support her baby on her own, she changed her mind and decides to marry Ben, as his family is financially stable. Amy and Ben get married with fake ID's, but discoverver that their marriage is null and void because they are both minors. They eventually break up after Amy's baby is born and Ben can't handle seeing her bond with Ricky. Adrian finds out she is pregnant with Ben's baby after a one-night stand essentially ruining Ben's chances of a relationship with Amy and they eventually get together. They marry and move in together before their baby is born with the financial support of Ben's father. After their baby is born stillborn Ben can't handle Adrian anymore and decides to divorce her against her wishes. At the end of the series, Ben follows Amy to New York, only to give up on her after Amy realizes that she was never really in love with Ben, and he was never really in love with her. The two then go their separate ways.

text: Ashley Juergens[edit]

text: Portrayed by India Eisley, Ashley Juergens is the youngest daughter of Anne and George, and Amy's younger sister. She is mature, observant, and sarcastic, tending to speak in a low, monotone voice. Ashley is the first member in the Juergens family to learn of Amy's pregnancy. She is often forgotten by her family and remarks that she could get away with anything. However, Ashley's main concern is keeping her family together. Ashley believed that Amy's baby would reunite her dividing family and worked hard to discourage Amy from adoption. After the baby was born, she named her nephew John since she thought it was simple and classic. During the third season she developed feelings for Ricky. She stays away from Ricky, for benefit of Amy and Ricky, but is told to back down by Amy so that she and Ricky can see if they can try to be a couple. Ashley passes her GED after a brief stint in home-schooling and travels across the US with her new friend, Toby. They end up broke in Florida and stay with his grandmother, earning money with various part-time jobs. Ashley returns home the day after Ricky's graduation and announces that she will be attending college in Florida in the fall. In season 5, Ashley's relationship with Toby has progressed into a sexual relationship. Her father is very upset once hearing this, but Ashley explains that they are in love and practicing safe-sex. After coming back from a trip to Europe with her mother, she finds out that she was accepted to a cooking school in Italy. Both George and Anne say no to the idea, so she ends up running away with the help of her grandmother Mimsy, who gives her ten thousand dollars.

text: Jack Pappas[edit]

text: Portrayed by Greg Finley II, Jack Pappas is a college freshman and quarterback on the football team. His stepfather, Reverend Stone, is the minister of the church where he and Grace first met. He cheats on Grace in the first episode when he has oral sex with Adrian, and is then caught kissing her at the school dance. Grace eventually forgives him, and they start to date in secret because of her parent's disapproval. To Jack's dismay, Ricky pretends to be dating Grace as a cover for her parent's. Their relationship ends again when a security camera catches Ricky saving Grace from two men after Jack left her in a bad part of town. He is shown to be clearly jealous over Ricky, which prompts him to tell Grace that he only started dating her because his step-father asked him to. He eventually breaks up with Grace and moves in with Tom in Grace's family's guest house, even though he still loves Grace. He later dates Madison and they break up after summer vacation. Jack and Madison reunite, and although they are back together, Madison becomes very jealous that Jack is living with Grace's family. He moves out of the guest house and into the big house (where Grace lives) because Tom's new girlfriend and her children move into the guest house with Tom. Jack's room is next to Grace's which makes Madison even more nervous about their relationship. Later on, Jack and Madison break up, because he is still in love with Grace. Jack is chosen to give the invocation at the graduation ceremony, and Grace helps him write it. At the end of season 4 they share a kiss to see if they still have feelings for each other. The kiss is captured on a cell phone, and the picture is sent to Grace's current boyfriend, Daniel. Jack is jubilant when Grace's boyfriend breaks up with her, but Grace's mother suggests that since he is going to college in a few months, perhaps he'd be better off just being friends with Grace and taking advantage of new college experiences. He tries to date by sleeping with a girl named Clementine, who is an old friend of Ricky's, but realizes that he still wants to be with Grace. After they get back together, Grace discovers his recent relationship with Clementine, and has trouble trusting him. Jack is in critical condition after a pimp beat him with a baseball bat in his dorm room for paying an underage prostitute without sex and helping her escape. Jack eventually ends up marrying Madison. They also move to New York. Jack becomes a coach at St. Francis

text: Grace Bowman[edit]

text: Portrayed by Megan Park, Grace Bowman is the biological daughter of Marshall and Kathleen Bowman and the younger sister of the adopted Tom Bowman. Grace is 18 years old. She is in 12th grade, and an ex-cheerleader. At the beginning of the show, Grace was a devout religious person and does her best to be stay true to her religion. Originally, she was in a relationship with Jack, but they had a lot of disagreements over whether or not to have sex. Grace believed in waiting till marriage, and even wore a promise ring to prove it. She and Jack later break up after he has oral sex with Adrian. She briefly becomes involved with Ricky, but breaks up with him after discovering that he's still sleeping with Adrian. Grace and Jack get back together when Amy has John. In the second season opener, she and Jack decide to have sex. She quickly regrets her decision after the sudden death of her father. She later on becomes involved with Grant, the cousin of Griffin. Grant and Grace bond over their shared desire to become doctors, and strengthen that bond over a summer at MED camp. In her endeavors to become a doctor, she visits Africa with her doctor step-father, where she cheats on Grant with Daniel, a college student. Grant and Grace later break up and she begins to date Daniel, but their relationship isn't smooth due to his greater maturity. Grace becomes jealous of Daniel's ex-girlfriend at the graduation party and Daniel leaves. Grace and Jack share a kiss the next morning after the party, which is captured on a cell phone by Daniel's ex-girlfriend, Raven. Raven texts the picture to Daniel, and he breaks up with Grace, realizing that she still has feelings for Jack. Grace later confesses to Adrian that she thinks she may still be in love with Jack. She and Jack end their engagement and she moves to New York and becomes a doctor.

text: George Juergens[edit]

text: Portrayed by Mark Derwin, George Juergens is the estranged husband of Anne Juergens, the father of Amy, Ashley and Robbie Juergens, and the maternal grandfather of John Juergens. George is a comically blunt, somewhat immature and often oblivious man, but one who loves his family and tries hard to protect them and keep them together. His first wife was Kathleen Bowman, a woman who married him for sex. George, a furniture salesman, met Anne while she was in college. He and Anne eloped shortly after discovering Anne was pregnant with Amy. Two years later, they had Ashley. It is later found out that he cheated on Anne with other women. The two get a divorce and remarried and separate again. He also has another son with Anne, Robie. He currently lives at his children's childhood home with his dog. When everyone moves out, he invites Ricky's mother, Nora, to move in with him as a roommate. She moves into Ashley's garage bedroom. George and Anne still feel a spark for each other, but Anne seems intent on seeing the divorce go through. After George realizes Anne really is gay and he has no more feelings for her, he starts to date his first wife Kathleen (Grace and Tom's mother) again. They realize they still have their spark and that they are still in love.

text: Anne Juergens[edit]

text: Portrayed by Molly Ringwald, Anne Juergens is the daughter of Mimsy and Robert, the divorced wife of George Juergens, the mother of Amy, Ashley and Robbie Juergens and the maternal grandmother of John Juergens. She is a responsible, practical, and naturally independent woman who tries to install the same virtues in her daughters. Anne met George while she was majoring in Women's Studies at college. When Anne discovered she had become pregnant with Amy, she reluctantly dropped out of college, married George and became a wife. Two years later, she had Ashley, and another 14 years after that, she had Robbie. She and George separated after she became tired of his womanizing and realized that she was not happy in the marriage. She dated an architect for a while, and they planned to marry when she became pregnant, thinking it was his child; he later confessed that he could not have children, and she realized that Robbie was George's son. She lived with her mother for a while after her separation from George, but when her mother went into a home for Alzheimer's patients, she was on her own, and began to see a high school sweetheart for companionship, but the relationship didn't go anywhere. She and George made an attempt to get back together and she took over the design portion of his furniture business, but again she finds poorly-hidden evidence that he was unfaithful, and resumed divorce proceedings. In season 5, after George spreads the truth as a rumor around town, Anne Juergens comes out to her family as a lesbian. She walks in her house one day when Nora (Ricky's birth mother) was having an AA meeting with all lesbians attending. Anne gets to know one of them closely and invited her to stay the night. They plan to go out on a date.

text: Leo Boykewich[edit]

text: Steve Schirripa portrays Leo Boykewich, Ben's widowed father. He owns the local butcher shop, and is known as "The Sausage King". Leo is one of the first people to suspect Amy's pregnancy due to her huge appetite and nausea. He even supported Ben's decision to marrying Amy since he met Ben's mother when they were in high school. He's usually portrayed as the voice of reason for many of the characters on the shows. Such as when he tells Ben off for believing that he can support Amy's baby with his money. He gives Ben and Ricky jobs at the butcher shop as a way to help support Amy. In the second season, Leo begins to date a woman named Betty, who is the prostitute Tom had once hired. We later learn from Betty that she was very upfront about her profession the first day she introduced herself to Leo, because she was afraid of embarrassing him. He later proposes to Betty, but she explains that she may still be married to her ex. He promises to hunt down her husband, who turns out to be dead, and they get married in an elaborate ceremony. Leo takes Ricky under his wing by allowing him to live in the upstairs apartment. He is upset when Ben and Adrian discover they are having a baby, and tries to caution Ben from marrying Adrian just because she is pregnant. Ben is insistent, however, so Leo purchases a condo for the newlyweds. When Ben is ambivalent about being married, Leo sternly tells him that he made the choice, and he now has to make the best of it. When the baby is stillborn, Leo tearfully breaks the news to Ben and Adrian's friends at the hospital, and then later supports Ben's decision to get a divorce. In Season 4, Leo questions whether or not he wants to be married to Betty anymore when he suspects that his longtime assistant, Camille, is in love with him. Even so, Leo decides to stick with the marriage because he believes that is the right thing to do. Betty later decides that she wants a divorce and Leo agrees to it. He later sends Camille flowers and a bracelet and invites her out to dinner. While talking in the car on the way to dinner Camille kisses Leo, and the two are later seen together at graduation. They get married in the fifth season, and decide to adopt a young girl who was the under-aged prostitute that Jack helped.

text: Recurring characters[edit]

text: The following is a list of characters that are, or at one time were, a recurring guest on the series.

text: Nora Underwood[edit]

text: Anne Ramsay portrays Nora Underwood, Ricky's biological mother. For the majority of the first season, she is a distant character in Ricky's past. She has been to jail a few times due to drug possession and Ricky often felt bitter towards her because she failed to protect him from his father's abuse. But in Season 3, episode 7, she comes back into his life, to spend time with her son before she gets put back in jail. Ruben Enriquez (Adrian's father), as a DA helps Ricky get his mother out of jail, as he is willing to try and forgive her. Later on in the season, the two begin to repair the relationship, however, she was unsure about telling him she has a girlfriend, but she later does, and is gratified when Ricky seems pleased for her. The relationship doesn't last, though, and after a night of binge drinking (with the purported intent of convincing Ben that he shouldn't drink) she moves out of Margaret and Shakur's home and moves in with George Juergens, who initially tries to make a play for her, but remains pals when he discovers that she is a lesbian. She is very proud of Ricky's accomplishments in spite of his shaky childhood.

text: Henry Miller & Alice Valko[edit]

text: Allen Evangelista portrays Henry 'Hank' Miller, has been Ben's friend since the third grade. He is now dating Alison 'Alice' Valko (who is portrayed by Amy Rider), who has also become a friend of Ben's and some of the girls in school. Alice is very smart and knows a lot of factual information, while Henry is a bit more social. They have and discuss sex quite often, but fairly maturely. In the first episode, Alice pointed out Amy to Ben. In season 4 Henry breaks up with Alice and the two try "shared custody" of Ben, which is awkward and doesn't work out. In the 13th episode of Season 4, Alice walks into a bedroom after a graduation party to find Henry in bed with Adrian. Angrily, she tells Ben what she found, and Ben tells Henry he is no longer welcome in his home. After Ben finds out that he can no longer date Dylan, a sad conversation with Alice turns into sex. Henry thinks that there is something going on that he doesn't know about and pressures Alice to tell him. Ben doesn't know that Alice told Henry, and is mad at him for kissing Dylan.

text: Marc Molina[edit]

text: Jorge Pallo portrays Marc Molina, who was the school guidance counselor and was a big hit with the girls at the start of the school year. Before Amy reveals her pregnancy to her two best friends, Lauren and Madison, they gab about the new counselor, asking if she has something better to talk about than him. He's always helping people, especially Ben and Adrian. He disappeared before the season break, with people saying that he ran off with Adrian, but no one really knew why he was gone. It was later revealed that he left to get married. We later find out that his wife was his crazy girlfriend that he talked about with Ben and also that he was once a cop until his wife made him quit the force. Marc believes he married the wrong person, but it is revealed that his wife is pregnant when she comes to Amy's baby shower. He eventually resigned because he needed a better job to support his growing family.

text: Mimsy Scott Levy[edit]

text: Alice Hirson portrays Mimsy, Anne's mother, Amy, Ashley and Robie's grandmother and John Juergens great-grandmother. She has the beginnings of Alzheimer's disease and recently moved to an assisted care home. It is stated that she likes everyone better than Anne, and Anne is reluctant to tell her about anything in her life, such as her marital problems with George as well as her pregnancy. Anne and Amy worry about her sometimes. Mimsy is reported as having suffered a slight stroke and therefore, Anne and George miss John's first birthday to go to her side. Mimsy surprises Anne and George with the news that she has married a gentleman named Eugene Levy. In season 5, Ashley takes advantage of her Alzheimer's and convinces Mimsy to give her $10,000 to run away to Italy for cooking school. Alice Hirson previously portrayed Jenny Jackson, mother of Annie Camden in 7th Heaven.

text: Kathleen Bowman[edit]

text: Josie Bissett, of Melrose Place fame, portrays Kathleen Bowman, who is the mother of Grace Bowman, adoptive mother of Tom Bowman, the ex-wife of George Juergens, and new wife of Jeff Tseguay. She cheated on George during their marriage. As a teen, Kathleen's mother did not let her have any physical contact with any boys. She told Grace that she only married George for sex. She waited until she married Marshall Bowman to have sex with him. She becomes a widow after Marshall dies in a private jet crash and began dating a younger man named Dr. Jeff Tseguay, a gynecologist, much to Grace's displeasure. Kathleen and Jeff are so excited that Grace suddenly seems to be in favor of the marriage that they impulsively decide to marry right away. Kathleen therefore changed her name from "Bowman" to "Tseguay". Kathleen tries to balance supervising Tom's special needs with his desire to be independent, and tries to get Grace to behave responsibly when it comes to sex. Kathleen then gets back together with George Juergens in a serious relationship.

text: Tom Bowman[edit]

text: Luke Zimmerman portrays Tom Bowman, Grace's adopted older brother, who has Down Syndrome. His mother died earlier in his life, then he was adopted by the Bowmans. With the normal drives of a young man, he is interested in sex—at one point, he calls an "escort" service and a prostitute named Betty comes in response to his call. They do not have sex, but she spends the evening talking with him and allowing him to confess his frustrations. Later, he meets Tammy and wants to marry her, despite having only been on one date with her. Tammy ends up marrying someone else. He sometimes refers to Ricky as "Drummer Boy" and cares deeply about Grace. He mistakes Adrian's manipulation of him to borrow money as interest in him, and tries to respond, with no luck. When it is first announced that Adrian is pregnant, Tom proposes to her, and promises to take care of her. She gently refuses him. He and Jack share the Bowman's guesthouse for a while when Tom is impatient for more independence that Kathleen is willing to allow him. Jack moves into the main house when Tom begins dating a woman with two children that he met on the bus on his way to work as a Vice President of Human Resources.

text: Dr. Marshall Bowman[edit]

text: John Schneider portrays Dr. Marshall Bowman, Grace's overprotective father. He's also the partner of the Juergens' pediatrician, Dr. Hightower, which is how he found out about Amy's pregnancy. Marshall later admits to Ricky that his brother was sexually abused by his neighbor and later committed suicide. Marshall dies when his private jet crashes, leaving Grace thinking the crash was all her fault because she had sex with her boyfriend, Jack, after Marshall told her not to. His body was cremated and spread on a hole in a golf course. It was discovered in Season 4, that Marshall had a relationship with another woman while he was in Zimbabwe and they had a son together named Jacob.

text: Madison Cooperstein[edit]

text: Renee Olstead portrays Madison Mildred Cooperstein. She is in 12th grade, she's one of Amy's best friends, and her values are defined by her Catholicism. Madison unintentionally spreads gossip and rumors, though she is a well-meaning girl. She dated Lauren's brother, Jason, and unintentionally spread the news of Amy's pregnancy. She feels ignored by Amy because she is spending more time with Ben than with her. Madison broke up with Jason but started to have feelings over the breakup. It is revealed that her mother died. Madison seems to have a crush on Jack and might have done something with him over the summer. She does not want a relationship with Jack despite fooling around with him. After Jack and Grace's relationship fizzles, Jack begins to date Madison. Madison, hoping to reassure Jack that she is a "free spirit" and doesn't want to trap him, tells Jack that she's not interested in children or marriage. This causes Jack to rethink the relationship because, as he tells her, the whole idea of dating is to find someone that you might want to marry. Since she says she doesn't want to marry, perhaps he should be dating elsewhere. Madison quickly recants and tells Jack that she is interested in a family and children, but not for a long time. They resume their relationship, and while Madison is seriously considering having sex with Jack, she confesses that she isn't quite ready, wanting the occasion to be special and wearing a pretty dress and having her make-up done. Jack tells her that he is fine with waiting. So, to get around having actual sex, Madison and Jack often have oral sex. After school ends, Madison sleeps over at the Bowman guest house (where Jack stays) and lies about where she spent the night. When her dad gets an email from Lauren, he forbids Madison and Jack to date. Madison later tries to date her former supervisor, whom her father discovers lied about his age, and proceeds to kick him out of his home. Madison lost her virginity to Jack after Adrian and Ben's wedding, but because she and Jack regret having sex, they decide to discontinue any sexual activity. At the graduation party Madison has sex with Lauren's boyfriend, Jesse. Lauren tells her that she hates her, orders her out of her house when Madison comes to apologize, and rips up a photo of the two of them. Lauren forgives her. Then they go to Berkeley because of their amazing singing voices. Then her and Jack get back together move to New York. They also get married. She becomes a great Broadway singer and Jack becomes a coach.

text: Lauren Treacy[edit]

text: Camille Winbush portrays Lauren Treacy, who is also in the 12th grade and one of Amy's best friends. She is smart, practical, and seems to be the voice of reason for Amy. Her father is Ricky's therapist. Along with Madison, Lauren also accidentally spread the news of Amy's pregnancy. She made out with Ricky one night in his car. She also feels ignored by Amy. Her parents are divorced, and her mother is remarried. Lauren is now dating Jesse, and plans to have sex with him when Madison and Jack have sex. After her parents find out that she and Jesse slept over at Jack's guest house and she lied about it, her father and mother ban her from seeing and being with Jesse. She and Jesse break up, but then get back together when they realize they still care for each other. Jesse throws an all-night graduation party, where he drinks too much and ends up in bed with Madison after Lauren makes it clear that she neither intends to drink or have sex that night. Angrily, she breaks up with Jesse and tells Madison that she hates her. Camille Winbush also previously guest starred on 7th Heaven for 6 episodes as Lynn Hamilton.

text: Jason Treacy[edit]

text: Andrew McFarlane portrays Jason Treacy, Lauren's older brother and Madison Cooperstein's ex-boyfriend. He's a member of the Grant High Football team and portrayed as an excellent student, proven by the fact that he was the only other student besides Grace Bowman to be accepted into the Young Healers Camp program, for students who aspire to be doctors. At med camp, he and Grace became extremely attracted to one another because of all the time they spent together, and eventually they kissed. However, before returning home, they agreed to only be friends, but Jason still broke up with Madison before the next school year began. Along with Grace and her new boyfriend, Grant, he also attended the Young Healers Camp again the following summer.

text: Dr. Jeff Tseguay[edit]

text: Reid Scott portrays Dr. Jeff Tseguay, Grace's step-father. Jeff met Kathleen during the aftermath of Marshall's death—his brother died in the same plane crash that killed Marshall. Kathleen and Jeff's relationship is inadvertently discovered by Jack when he is in a drug store and witnesses Kathleen and Jeff purchasing contraceptives. He agrees not to tell Grace, but Kathleen decides to go ahead and tell Grace anyway, knowing that her interest in another man only six months after Marshall's death will deeply upset her. One evening, Kathleen is at Jeff's house and Jeff decides not to answer a phone call from his mother. His mother becomes concerned and bursts in on the couple talking in bed, much to Jeff's chagrin, Kathleen's embarrassment, and his mother's interest. Their relationship escalates quickly, and upon Grace's pretense at encouragement, they decide to marry. The day after the wedding, Jeff talks to Grace and tells her that he feels that they got off on the wrong foot, and, as her new stepfather and as an obstetrician/gynecologist, invites her to talk about her misgivings. During the talk, Grace begins to sort out her conflicted feelings about sex. Jeff later joins a medical team working for an extended period in Africa, where Grace visits him and meets Daniel. Jeff invites Kathleen to join him in Africa for a few months, and although tempted, she doesn't feel that she can leave Tom and Grace.

text: Betty Boykewich[edit]

text: Jennifer Coolidge portrays Betty, who meets and interests Leo Boykewich. She is upfront about telling him that she has been a prostitute, because she doesn't want him embarrassed when he finds out, but he decides he doesn't care. He discovers that she can't marry him because she is still married to a man she hasn't seen in a long time. Leo locates her husband, only to find that he has died, and he proposes. When Ben is conflicted over having sex with Adrian, Betty offers to listen to his problems, but Ben rudely turns her away, telling her he doesn't need advice from a prostitute. She is hurt, but soon bounces back. When Ben sincerely apologizes for his outburst, she assures him that she has already forgotten it, and goes on to encourage Ben to act on his feelings. Betty and Leo are married in a lavish wedding with Ben inviting all his friends to celebrate. Betty clumsily but earnestly attempts to console Adrian after the loss their baby. In season 4 she decides that she realizes that Leo is not happy and tells him she wants a divorce and wants to go to college. In one of the last episodes of the season her mother dies and while awaiting a flight on her soon-to-be ex-husband's private jet she is approached by a divorce lawyer.

text: Robert "Bob" Underwood[edit]

text: Bryan Callen portrays Robert "Bob" Underwood, Ricky's biological father who has been to jail for drugs and child molestation. In Season 1 during one episode he comes back to find Ricky, and wants to sell Ricky and Amy's baby. Later, he is caught with drugs and sent back to prison. Bryan Callen also previously guest starred on 7th Heaven for 9 episodes as George 'Vic' Vickery Petrowski.

text: Margaret Shakur[edit]

text: L. Scott Caldwell portrays Margaret Shakur, Ricky's foster mother and John Juergens' foster grandmother. Margaret and her husband love Ricky as their own, and are proud to be his parents. Later, Margaret and Sanjay have dinner with Anne and George to discuss Ricky's custody case, and expressing a desire to be a part of John's life. Margaret helped Adrian with her decision about whether or not to terminate her unplanned pregnancy. Later, Ricky's birth mother, Nora, moves in with Margaret and Sanjay when starting her life over, and they have become good friends. Margaret decides to take in one of Ricky's former foster brothers, Ethan, who ends up in juvenile detention after sexting nude pictures of an underage girl to his friends when she breaks up with him. Because of overcrowding in juvenile detention, Ethan will return to live with Margaret.

text: Cindy Lee Enriquez[edit]

text: Paola Turbay portrays Cindy Lee, Adrian's mother. Cindy got pregnant with Adrian as a teenager on purpose because she wanted the love of a baby, but her guilt of trapping Ruben Enriquez, Adrian's father, into being a father caused her to keep Ruben out of their lives. She raised Adrian alone and worked as a flight attendant; causing her to be away from home a lot. At the start of the show, she and George Jurgens had an affair that ended around the time George found out about Amy's pregnancy. She was also unaware of Adrian's affairs and her moniker as the "school slut" until Ruben told her. Despite this, Cindy continues to work, leaving Adrian alone, where Adrian continues to have sex. Cindy and Ruben later reunite after he leaves his wife, and she declines a job promotion in New York so they could get married. After a minor case of cold feet, Cindy and Ruben decide to get married the day before Leo and Betty's wedding in a judge's office. Much to Cindy's consternation, Ruben's mother has sent a completely inappropriate wedding dress to wear — an ugly red, flouncy dress several sizes too large. After a moment of anger, Cindy shrugs and she and Ruben are married, with Adrian as a witness. When Adrian reveals that she's pregnant, Cindy tells her daughter that she will stand behind Adrian, whether or not she decides to have an abortion. This spawns an argument between her and Ruben since he's Catholic. They later make up and support Adrian's decision to have the baby. Cindy and her husband are present for Adrian and Ben's wedding, and she later try's to comfort her daughter after the baby's stillbirth.

text: Ruben Enriquez[edit]

text: Philip Anthony-Rodriguez portrays Ruben Enriquez, Adrian's father and the ex-boyfriend of Cindy. He was not involved with Adrian during her childhood years because he and Cindy made a deal not to see each other. When Adrian eventually finds him, Ruben tells Adrian he wants nothing do with her, but later decides to help her turn her life around for the better. Ruben is an Assistant District Attorney and is married for the third time. Adrian is his second biological child (he has a biological son in Mexico), however, he is the stepfather to two sons. For confidentiality reasons, he could not tell Adrian that he had known the truth about Ricky having been sexually abused. He and Cindy marry before a judge, "Fast Eddy", the day before Leo and Betty marry. When his daughter becomes pregnant, Ruben strongly objects to the idea of her having an abortion. This causes conflict between Ruben and his wife, who supports Adrian's decision. Adrian chose to keep the baby, and Ruben couldn't have been happier. When Adrian's daughter, later named "Mercy" is born stillborn, he blames himself for pushing Adrian to keep the baby instead of having an abortion.

text: Rev. Sam Stone[edit]

text: Tom Virtue portrays Rev. Sam Stone, Jack's stepfather and the minister at the local church. Jack told him why Grace thinks her dad died. He tried, unsuccessfully, to make Grace see that she and Jack having sex had nothing to with her father's death. He also helped Amy find couples to adopt her unborn baby (John) when she was pregnant. After offered a job at his Alma Mater in Phoenix, Arizona as the head of the Philosophy department, he gives up the church and moves with his wife, leaving Jack to complete his senior year. He makes a cameo appearance to marry Ben and Adrian.

text: Griffin[edit]

text: Brando Eaton portrays Griffin, who is in 9th grade like Ashley, and is her friend. He and Ashley clicked as friends when he asked her to sit with him at lunch. After she asks him if all he wants is to have sex with her, Griffin tells Ashley that he is gay. George likes Griffin after meeting him because Ashley did not pick a guy friend who only wants her for sex. It's revealed that his two older brothers are also gay. He fixes Ashley up with his cousin, Grant, and brings his date, Michael, to Leo and Betty's wedding. After Ashley uses Grant, Griffin decides to introduce him to Grace Bowman. In return, Grace introduces Griffin to Peter, a guy she knew from church, and it was an instant connection for both couples.

text: Grant[edit]

text: Grant Harvey portrays Grant, Griffin's awkward but engaging cousin, who is not gay and is interested in Ashley. He is put up to a blind date with Ashley by Griffin, and finds himself attracted to her. At first, George isn't concerned, thinking that since Grant is related to Griffin, he must be gay, too. He is taken aback to discover that Grant is not gay, but decides to trust Ashley not to make the same mistake that Amy did. He wants to have sex with Ashley. After a party held by Leo and Ben, Grant finds interest in Grace, and is now dating her. He and Grace stay abstinent through their summer at Med Camp, and have sex after school starts when Grant's parents are out of town. Grant then told Grace that he loved her. Later, Grant's parents come to the Bowman-Tseguay residence and it is found that Grant's father is quite old, but charms the hearts of both Grace and Kathleen..

text: Katelyn O'Malley[edit]

text: Beverley Mitchell portrays Katelyn O'Malley. Mitchell is the third person from the show that previously starred on 7th Heaven; Mackenzie Rosman was the second, playing a recurring role as Zoe and Christopher Michael was the first, playing the football coach. Katelyn is the most recent school guidance counselor. It is revealed in season 4 that like Ben and Adrian, she lost a child when her baby died of SIDS. She also explains that her marriage fell apart as well when her husband became an alcoholic.

text: Dylan[edit]

text: Dylan is introduced during the graduation party. Henry points her out and Ben goes after her. Dylan's parents are very protective over her and it takes a while for them to be convinced that it is okay for them to date. Ben's dad and Dylan's parents catch Dylan and her friends smoking pot in Ben's room. They are then forbidden to see each other. After some convincing they are allowed to go out again but they accidentally burn down Dylan's school, and they are forbidden to see each other again. Even though her friend, Wendy, told her that she overheard Ben telling Amy that he still loves her, she still wants to date Ben. They come up with this idea that her parents could meet Henry and pretend to go out with Henry, but instead meet Ben. Ben's dad finds out and forbids him from going. At her house, Henry is mad at Ben for sleeping with Alice and plans to make revenge by going out with Dylan for real. So he forces her to stay home and have a real date. Dylan is furious with Henry, but they still kiss. Dylan then finds out that Ben and Alice slept together and doesn't really want to go out with Ben anymore so she gives Henry a chance. She is portrayed by Ana Lucasey.

text: Jesse[edit]

text: Austin Stowell portrays Jesse. He became Lauren's boyfriend in season 2. After sleeping at Jack's guest room with Madison and Lauren, Lauren is banned from seeing Jesse. At his graduation party, where he drinks too much, Lauren discovers him sleeping with Madison.

text: Kathy[edit]

text: Kathy is portrayed by Cierra Ramirez, introduced in the 100th episode as a new freshman who Amy mentors as part of a senior project. She got pregnant by her much older ex-boyfriend, and plans on giving her baby girl up for adoption. She is initially wary about talking to Amy because unlike her, she chose to raise a child as a teenager. Kathy eventually opens up to her about her worries on not having friends because of her condition. She currently lives with her grandmother because her parents kicked her out. Kathy explains early on that even though her baby will have an open adoption, she has no plans to be involved in the child's life. She meets Ethan and they start connecting about their histories and even go on a double-date with Amy and Ricky. Their relationship hits a speed bump in the road after Ethan makes a disastrous first impression to the prospective parents, who later tell Kathy to break-up with him. They quickly get back together in the fall season finale. In the holiday special, Kathy goes into labor on Christmas Eve and gives birth to a baby girl on Christmas Day. The adoptive parents name her Hedy. She is portrayed by Cierra Ramirez.

text: Ethan[edit]

text: Played by Michael Grant, Ethan is Ricky's 14-year-old foster brother who ran away from their house a few years after stealing a knife from Margaret and Shaker. He first appears when he gets into trouble for sending naked pictures of his ex-girlfriend to everyone in his contacts, which ultimately lands him in juvenile detention. Margaret decides to take him in again, and forces him to go back to school. In season 4 he is forced to go to summer school and immediately gets into trouble for stealing condoms from the nurse's office. Despite his actions, Ricky still tries to install sense in him remembering his early days before he met Amy. He begins dating Kathy, who is pregnant with her ex-boyfriend's child. They decide to take their relationship slow, but Ethan has trouble respecting Kathy's boundaries. Such as when he meets the perspective parent's of Kathy's unborn daughter, and asks rude and personal questions about them. Kathy breaks up with him when her perspective parent's think he is too unstable to be around. Ethan later confides to Kathy that his biological father injured him when he was a kid, causing his distrust in adults. After meeting Kathy, Ethan tries several times to get advice from Ben on how to be a good boyfriend to someone who is having a child with another guy, but Ben show's no interest in helping him. In the episode "Holly Rollers", he is shown to be a talented piano player. Then him and Amy start getting closer and closer while Amy and Ricky get farther.

text: Minor characters[edit]

text: The following is a list of characters that appear on the show, but usually do not add to the overall plot or story line of the series.

text: Mrs. Virginia Molina[edit]

text: Constance Marie portrays Mrs. Virginia Molina, Mr. Molina's new wife. They are expecting a baby around the same time as Amy. She shows up at Amy's baby shower after being invited by Joe.

text: John Juergens Underwood[edit]

text: Amy and Ricky's now three-year-old son whom they conceived on a night at band camp when Amy was a freshman and when Ricky was a sophomore in high school. Ashley (Amy's sister) is the one who suggested John's name because "his life was going to be complicated already, so we might as well give him an easy name." His birthday is 06/06/09. His parents Amy and Ricky break apart from their marriage plans and Amy goes to college, leaving Ricky as a single father.

text: Mrs. Stone[edit]

text: Kristin Bauer van Straten portrays Mrs. Stone, Jack's mother. She met her second husband at grief counseling. Her voice is heard once yelling at Jack when he throws a football into the window. She and her husband tell Jack about his new job in Arizona, requiring Jack to find a new place to live to prevent him from relocating during his senior year. And at one of the last episodes of 2012 she shows up at the last few minutes of the show to pray while Jack lies in his hospital room comotized he comes back after jack gets into coma

text: Peter[edit]

text: Kristopher Higgins portrays Peter, who is introduced in the Season 3 episode "Chicken Little". Peter becomes a love interest for Griffin when Grace sets them up believing Peter is gay. After talking with both his father and Griffin, Peter comes out as gay, and pursues a relationship with Griffin.

text: Mercedes[edit]

text: Katelyn Tarver portrays Mercedes, who is one of the friends of Dylan, Raven, and Wendy. Her first appearance was in Smokin' Like a Virgin, although she was probably at Dylan's party (before everyone ended up at the cabin next door, where Jesse and everyone else from the main cast was). She went over to Ben's house with Dylan and she smoked pot because she was depressed after her mom died and her mom had a prescription.


document_title: Mean

question_text: what does the mean of probability distribution tell us

text: Mean

text: Types of mean[edit]

text: Pythagorean means[edit]

text: Arithmetic mean (AM)[edit]

text:
The arithmetic mean (or simply "mean") of a sample

x

1

,

x

2

,
…
,

x

n

{\displaystyle x_{1},x_{2},\ldots ,x_{n}}

, usually denoted by

x
¯

{\displaystyle {\bar {x}}}

, is the sum of the sampled values divided by the number of items in the example

text: For example, the arithmetic mean of five values: 4, 36, 45, 50, 75 is:

text: Geometric mean (GM)[edit]

text: The geometric mean is an average that is useful for sets of positive numbers that are interpreted according to their product and not their sum (as is the case with the arithmetic mean) e.g. rates of growth.

text: For example, the geometric mean of five values: 4, 36, 45, 50, 75 is:

text: Harmonic mean (HM)[edit]

text: The harmonic mean is an average which is useful for sets of numbers which are defined in relation to some unit, for example speed (distance per unit of time).

text: For example, the harmonic mean of the five values: 4, 36, 45, 50, 75 is

text: Relationship between AM, GM, and HM[edit]

text: AM, GM, and HM satisfy these inequalities:

text: Equality holds if and only if all the elements of the given sample are equal.

text: Statistical location[edit]

text: In descriptive statistics, the mean may be confused with the median, mode or mid-range, as any of these may be called an "average" (more formally, a measure of central tendency). The mean of a set of observations is the arithmetic average of the values; however, for skewed distributions, the mean is not necessarily the same as the middle value (median), or the most likely value (mode). For example, mean income is typically skewed upwards by a small number of people with very large incomes, so that the majority have an income lower than the mean. By contrast, the median income is the level at which half the population is below and half is above. The mode income is the most likely income, and favors the larger number of people with lower incomes. While the median and mode are often more intuitive measures for such skewed data, many skewed distributions are in fact best described by their mean, including the exponential and Poisson distributions.

text: Mean of a probability distribution[edit]

text:
The mean of a probability distribution is the long-run arithmetic average value of a random variable having that distribution. In this context, it is also known as the expected value. For a discrete probability distribution, the mean is given by

∑
x
P
(
x
)

{\displaystyle \textstyle \sum xP(x)}

, where the sum is taken over all possible values of the random variable and

P
(
x
)

{\displaystyle P(x)}

 is the probability mass function. For a continuous distribution,the mean is

∫

−
∞

∞

x
f
(
x
)

d
x

{\displaystyle \textstyle \int _{-\infty }^{\infty }xf(x)\,dx}

, where

f
(
x
)

{\displaystyle f(x)}

 is the probability density function. In all cases, including those in which the distribution is neither discrete nor continuous, the mean is the Lebesgue integral of the random variable with respect to its probability measure. The mean need not exist or be finite; for some probability distributions the mean is infinite (+∞ or −∞), while others have no mean.

text: Generalized means[edit]

text: Power mean[edit]

text: The generalized mean, also known as the power mean or Hölder mean, is an abstraction of the quadratic, arithmetic, geometric and harmonic means. It is defined for a set of n positive numbers xi by

text: By choosing different values for the parameter m, the following types of means are obtained:

text:
m
→
∞

{\displaystyle m\rightarrow \infty }

maximum of

x

i

{\displaystyle x_{i}}

m
=
2

{\displaystyle m=2}

quadratic mean

m
=
1

{\displaystyle m=1}

arithmetic mean

m
→
0

{\displaystyle m\rightarrow 0}

geometric mean

m
=
−
1

{\displaystyle m=-1}

harmonic mean

m
→
−
∞

{\displaystyle m\rightarrow -\infty }

minimum of

x

i

{\displaystyle x_{i}}

tag: table

text: ƒ-mean[edit]

text: This can be generalized further as the generalized f-mean

text: and again a suitable choice of an invertible ƒ will give

text:
f
(
x
)
=
x

{\displaystyle f(x)=x}

arithmetic mean,

f
(
x
)
=

1
x

{\displaystyle f(x)={\frac {1}{x}}}

harmonic mean,

f
(
x
)
=

x

m

{\displaystyle f(x)=x^{m}}

power mean,

f
(
x
)
=
ln

x

{\displaystyle f(x)=\ln x}

geometric mean.

text: Weighted arithmetic mean[edit]

text: The weighted arithmetic mean (or weighted average) is used if one wants to combine average values from samples of the same population with different sample sizes:

text:
The weights

w

i

{\displaystyle w_{i}}

 represent the sizes of the different samples. In other applications they represent a measure for the reliability of the influence upon the mean by the respective values.

text: Truncated mean[edit]

text: Sometimes a set of numbers might contain outliers, i.e., data values which are much lower or much higher than the others. Often, outliers are erroneous data caused by artifacts. In this case, one can use a truncated mean. It involves discarding given parts of the data at the top or the bottom end, typically an equal amount at each end, and then taking the arithmetic mean of the remaining data. The number of values removed is indicated as a percentage of total number of values.

text: Interquartile mean[edit]

text: The interquartile mean is a specific example of a truncated mean. It is simply the arithmetic mean after removing the lowest and the highest quarter of values.

text: assuming the values have been ordered, so is simply a specific example of a weighted mean for a specific set of weights.

text: Mean of a function[edit]

text:
In some circumstances mathematicians may calculate a mean of an infinite (even an uncountable) set of values. This can happen when calculating the mean value

y

ave

{\displaystyle y_{\text{ave}}}

 of a function

f
(
x
)

{\displaystyle f(x)}

. Intuitively this can be thought of as calculating the area under a section of a curve and then dividing by the length of that section. This can be done crudely by counting squares on graph paper or more precisely by integration. The integration formula is written as:

text: Care must be taken to make sure that the integral converges. But the mean may be finite even if the function itself tends to infinity at some points.

text: Mean of angles and cyclical quantities[edit]

text: Angles, times of day, and other cyclical quantities require modular arithmetic to add and otherwise combine numbers. In all these situations, there will not be a unique mean. For example, the times an hour before and after midnight are equidistant to both midnight and noon. It is also possible that no mean exists. Consider a color wheel -- there is no mean to the set of all colors. In these situations, you must decide which mean is most useful. You can do this by adjusting the values before averaging, or by using a specialized approach for the mean of circular quantities.

text: Fréchet mean[edit]

text: The Fréchet mean gives a manner for determining the "center" of a mass distribution on a surface or, more generally, Riemannian manifold. Unlike many other means, the Fréchet mean is defined on a space whose elements cannot necessarily be added together or multiplied by scalars. It is sometimes also known as the Karcher mean (named after Hermann Karcher).

text: Other means[edit]

text:
Arithmetic-geometric mean
Arithmetic-harmonic mean
Cesàro mean
Chisini mean
Contraharmonic mean
Elementary symmetric mean
Geometric-harmonic mean
Grand mean
Heinz mean
Heronian mean
Identric mean
Lehmer mean
Logarithmic mean
Moving average
Neuman-Sándor mean
Root mean square (quadratic mean)
Rényi's entropy (a generalized f-mean)
Spherical mean
Stolarsky mean
Weighted geometric mean
Weighted harmonic mean

tag: ul

text: Distribution of the sample mean[edit]

text: The arithmetic mean of a population, or population mean, is often denoted μ. The sample mean (the arithmetic mean of a sample of values drawn from the population) makes a good estimator of the population mean, as its expected value is equal to the population mean (that is, it is an unbiased estimator). The sample mean is a random variable, not a constant, since its calculated value will randomly differ depending on which members of the population are sampled, and consequently it will have its own distribution. For a random sample of n observations from a normally distributed population, the sample mean distribution is normally distributed with mean and variance as follows:

text: Often, since the population variance is an unknown parameter, it is estimated by the mean sum of squares; when this estimated value is used, the distribution of the sample mean is no longer a normal distribution but rather a Student's t distribution with n − 1 degrees of freedom.


document_title: List of Academy Award winners and nominees from India

question_text: who won the first oscar award in india

question_tokens: who won the first oscar award in india

text: Winners and nominees[edit]

text:
List of the Indian Oscar nominee(s)/recipient(s), also showing the year, film, category, and result

Year
Nominee(s)/recipient(s)
Film
Category/Honorary Award
Result/received
Ref.

1958
(30th)
Mehboob Khan
Mother India
Best Foreign Language Film
Nominated[N 1]
[3]

1961
(33rd)
Ismail Merchant
The Creation of Woman
Best Short Subject (Live Action)
Nominated
[5]

1979
(51st)
Vidhu Vinod Chopra and K.K.Kapil
An Encounter with Faces
Best Documentary (Short Subject)
Nominated
[6]

1983
(55th)
Bhanu Athaiya
Gandhi
Best Costume Design
Won
[7]

Ravi Shankar
Best Original Score
Nominated

1987
(59th)
Ismail Merchant
A Room with a View
Best Picture
Nominated
[8]

1989
(61st)
Mira Nair
Salaam Bombay!
Best Foreign Language Film
Nominated
[9]

1992
(64th)
Satyajit Ray
Pather Pachali
Honorary Award[N 2]
Received
[12]

1993
(65th)
Ismail Merchant
Howards End
Best Picture
Nominated
[13]

1994
(66th)
Ismail Merchant
The Remains of the Day
Best Picture
Nominated
[14]

2002
(74th)
Ashutosh Gowarikar
Lagaan
Best Foreign Language Film
Nominated
[15]

2005
(77th)
Ashvin Kumar
Little Terrorist
Best Short Subject (Live Action)
Nominated
[16]

2007
(79th)
Deepa Mehta
Water
Best Foreign Language Film[N 3]
Nominated
[17]

2009
(81st)
Resul Pookutty
Slumdog Millionaire
Best Sound Mixing
Won
[18]

A.R.Rahman
Best Original Score
Won

A.R.Rahman and Gulzar
Best Original Song
Won

2011
(83rd)
A.R.Rahman
127 Hours
Best Original Score
Nominated
[19]

A.R.Rahman
Best Original Song
Nominated

2013
(85th)
Bombay Jayashri
Life of Pi
Best Original Song
Nominated
[20]

2016
Rahul Thakkar
n/a
Sci-Tech Award
Received
[21][22]

2016
Cottalango Leon
n/a
Sci-Tech Award
Received
[23][24]

2018
Vikas Sathaye
n/a
Sci-Tech Award
Received
[25][26]


document_title: Australian citizenship test

question_text: four aspects of being an australian that are tested in the australian citizenship test

text: Australian citizenship test

text: History[edit]

text: In December 2006, it was announced that applicants for Australian citizenship who are over 18 and under 60 years old will need to pass an Australian citizenship test. The objective of the test is to prove an applicant's grasp of English language and understanding of Australia’s "values", history, traditional and national symbols. Citizenship applicants are required to study a booklet produced by the Department of Immigration and Citizenship.

text: On 2 January 2008, it was announced that the test would be reviewed when statistics showed that over 20% of those sitting the test failed on their first attempts.[2] On 28 April 2008 the Minister for Immigration and Citizenship, Senator Chris Evans, announced the appointment of an independent committee to conduct a review of the Australian citizenship test since its implementation on 1 October 2007.[3] This review was commissioned to examine the operation of the citizenship test after six months experience and whether there were ways to improve its operation and effectiveness as the pathway for residents to become Australian citizens. On 22 November 2008, the Minister for Immigration and Citizenship, Chris Evans, released the Citizenship Test Review Report Moving Forward … Improving Pathways to Citizenship and the Government’s response.[4] The report and the government's response are located online.[5]

text: On 19 October 2009, changes to the citizenship test came into effect. Under the new rules, a mark of 75% (15 out of 20 questions correct) is required to pass.[6] Previously, a mark of 60% plus answering three mandatory questions correctly was required. Applicants will need to pass the test before a decision is made on their citizenship application, i.e. the application must be lodged before the test takes place.[7]

text: Test format[edit]

text: The computer based test consists of 20 multiple choice questions drawn randomly from a pool of 200 confidential questions. The test is only available in English. Applicants have 45 minutes to complete the test. The material is drawn from the official guide "Our common bond" published by the Australian Government department of Immigration and Citizenship.

text: Scheduling a time to take the test can be done by the Department of Immigration & Citizenship (DIAC). Wait times vary widely, and applicants may need to wait a considerable amount of time. As of 17 February 2009, one would need to wait almost four months to secure an appointment in central Sydney and over three months in Parramatta. In less congested areas, wait times are considerably less, if any; in Adelaide, for instance, an applicant needs to make an appointment online or by paper application to Adelaide DIAC office anytime.[8]

text: Questions and answers[edit]

text: This article needs to be updated. Please update this article to reflect recent events or newly available information. (June 2012)

text: Although the following are not necessarily correct answers, they are correct in the context of the test.

text:
Which one of these is a responsibility for every Australian citizen? (Join with Australians to defend Australia and its way of life, should the need arise)
Which one of these values is important in modern Australia? (Everyone has equality of opportunity)
What is Australia's national floral emblem? (The golden wattle)
What is a Bill? (A proposed law that has not yet passed through parliament)
In what year did Federation take place? (1901)
Which day of the year is Australia Day? (26 January)
What is the first line of Australia's national anthem? ("Australians all let us rejoice")
What is the population of Australia? (approx 24 million)
In what city is the Parliament House of the Commonwealth Parliament located? (Canberra)
Who is the Queen's representative in Australia? (the governor-general)
How are Members of Parliament chosen? (by election)
Who do Members of Parliament represent? (the people of their electorate)
After a federal election, who forms the new government? (the political party or coalition of parties which wins a majority of seats in the House of Representatives)
What are the colours on the Australian flag? (red, white and blue)
Who is the head of the Australian Government? (the prime minister)
What are the three levels of government in Australia? (Commonwealth, State or Territory and local)
In what year did the European settlement of Australia start? (1788)
Serving on a jury if required is a responsibility of Australian citizenship: true or false? (true)
In Australia, everyone is free to practise the religion of their choice, or practise no religion: true or false? (true)
To be elected to the Commonwealth Parliament you must be an Australian citizen: true or false? (true)
As an Australian citizen, I have the right to register my baby born overseas as an Australian citizen: true or false? (true)
Australian citizens aged 18 years or over are required to enrol on the electoral register: true or false? (true)
What do we remember on Anzac Day? (The landing of the Australian and New Zealand Army Corps at Gallipoli, Turkey)
What are the colours of the Australian Aboriginal Flag? (Black, red and yellow)
Which official symbol of Australia identifies Commonwealth property? (Commonwealth Coat of Arms)
Which of these statements about Australia’s system of government is correct? (The government is elected by the people)
Which of these is an example of freedom of speech? (People can peacefully protest against government decisions)
Which of these statements about government in Australia is correct? (Government in Australia)
Which of these is an example of equality in Australia? (Men and women have the same rights)
Which of these is a responsibility of Australian citizens aged 18 years or over? (To vote in elections)
Which of these is a responsibility of Australian citizens aged 18 years or over? (To serve on a jury if called to do so)
Which of these statements about passports is correct? (Australian citizens can apply for an Australian passport)
Which of these is a role of the Governor-General? (The signing of Bills passed by the Australian Parliament)
Which of these statements about state governments is correct? (Each state has its own constitution)
What is the name given to the party or coalition of parties with the second largest number of members in the House of Representatives? (The Opposition)
What is the name of a proposal to make a law in parliament? (Bill)
Who maintains peace and order in Australia? (Police)

text: Notes[edit]

text:
Jump up ^ "Understanding the Australian Citizenship Test process".
Jump up ^ Article highlighting failure rates
Jump up ^ "Archived copy". Archived from the original on 16 May 2009. Retrieved 2009-03-31.  Independent committee to review citizenship test
Jump up ^ "Archived copy". Archived from the original on 24 March 2009. Retrieved 2009-03-31.  New Citizenship test to focus on responsibilities and privileges
Jump up ^ "Archived copy". Archived from the original on 31 March 2009. Retrieved 2009-03-31.
Jump up ^ [1] Australian Citizenship Practice Test
Jump up ^ [2] About the citizenship test
Jump up ^ Department of Immigration & Citizenship website detailing how to make an appointment
Jump up ^ "Australian Citizenship Test practice questions" (PDF). Retrieved 26 June 2012.