- published: 28 May 2014
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In statistics, mean has two related meanings:
There are other statistical measures that should not be confused with averages - including 'median' and 'mode'. Other simple statistical analyses use measures of spread, such as range, interquartile range, or standard deviation. For a real-valued random variable X, the mean is the expectation of X. Note that not every probability distribution has a defined mean (or variance); see the Cauchy distribution for an example.
For a data set, the mean is the sum of the values divided by the number of values. The mean of a set of numbers x1, x2, ..., xn is typically denoted by Failed to parse (Missing texvc executable; please see math/README to configure.): \bar{x} , pronounced "x bar". This mean is a type of arithmetic mean. If the data set were based on a series of observations obtained by sampling a statistical population, this mean is termed the "sample mean" (Failed to parse (Missing texvc executable; please see math/README to configure.): \bar{x} ) to distinguish it from the "population mean" (Failed to parse (Missing texvc executable; please see math/README to configure.): \mu or Failed to parse (Missing texvc executable; please see math/README to configure.): \mu x). The mean is often quoted along with the standard deviation: the mean describes the central location of the data, and the standard deviation describes the spread. An alternative measure of dispersion is the mean deviation, equivalent to the average absolute deviation from the mean. It is less sensitive to outliers, but less mathematically tractable.
Dwayne Michael Carter, Jr. (born September 27, 1982), better known by his stage name Lil Wayne, is an American rapper. At the age of nine, Lil Wayne joined Cash Money Records as the youngest member of the label, and half of the duo, The B.G.'z, with B.G.. In 1997, Lil Wayne joined the group Hot Boys, which also included rappers Juvenile, B.G., and Young Turk. Hot Boys debuted with Get It How U Live! that year. Lil Wayne gained most of his success with the group's major selling album Guerrilla Warfare, released in 1999. Also in 1999, Lil Wayne released his Platinum debut album Tha Block Is Hot, selling over one million copies in the U.S.
Although his next two albums Lights Out (2000) and 500 Degreez (2002) were not as successful (only reaching Gold status), Lil Wayne reached higher popularity in 2004 with Tha Carter, which included the single "Go D.J." Wayne also appeared on the Destiny's Child top ten single "Soldier" that year. In 2005, the sequel to Tha Carter, Tha Carter II, was released. In 2006 and 2007, Lil Wayne released several mixtapes and appeared on several popular rap and R&B singles. His most successful album, Tha Carter III, was released in 2008 and sold over 1 million copies in the U.S. its first week of release. It included the number-one single "Lollipop" featuring Static Major. It also includes the singles "A Milli" and "Got Money" featuring T-Pain and won the Grammy Award for Best Rap Album.
Lionel Andrés Messi (Spanish pronunciation: [ljoˈnel anˈdɾes ˈmesi], born 24 June 1987) is an Argentine footballer who plays in La Liga for FC Barcelona and is the captain of the Argentina national team, mainly as a forward.
By the age of 21, Messi had received Ballon d'Or and FIFA World Player of the Year nominations. The following year in 2009 he won both the Ballon d'Or and FIFA World Player of the Year, and won the inaugural FIFA Ballon d'Or in 2010 and 2011. He also won the 2010–11 UEFA Best Player in Europe Award. Messi is the fourth football player to win three Ballons d'Or, after Johan Cruyff, Michel Platini and Marco van Basten and the second player to win three consecutive Ballons d'Or, after Michel Platini. His playing style and small stature have drawn comparisons to Diego Maradona, who himself declared Messi as his "successor".
Messi has won five La Liga titles and three Champions League titles. In 2012, Messi made UEFA Champions League history by becoming the first player to score five goals in one match, in a 7–1 win against Bayer Leverkusen. With two goals in the next round against A.C. Milan, he matched José Altafini's record of 14 goals in a single UEFA Champions League/European Cup season. He also became the first player to top-score in four successive European Champion Clubs' Cup campaigns. He set the world record for most goals scored in a season during the 2011–12 season, with 73 goals.