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, ..., x_n 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.

Willard Mitt Romney (born March 12, 1947) is an American businessman and the presumptive nominee of the Republican Party for President of the United States in the 2012 election. He was the 70th Governor of Massachusetts (2003–07).

The son of Lenore and George W. Romney (Governor of Michigan, 1963–69), he was raised in Bloomfield Hills, Michigan. In 1966, after one year at Stanford University, he left the United States to spend thirty months in France as a Mormon missionary. In 1969, he married Ann Davies, and the couple had five children together. In 1971, he earned a Bachelor of Arts degree in English from Brigham Young University and, in 1975, a joint Juris Doctor and Master of Business Administration from Harvard University as a Baker Scholar. He entered the management consulting industry, which in 1977, led to a position at Bain & Company. Later serving as Chief Executive Officer, he helped bring the company out of financial crisis. In 1984, he co-founded the spin-off Bain Capital, a private equity investment firm that became highly profitable and one of the largest such firms in the nation. His net worth is estimated at $190–250 million, wealth that has helped fund his political campaigns. Active in The Church of Jesus Christ of Latter-day Saints, he served as Ward Bishop and later Stake President in his area near Boston. He ran as the Republican candidate in the 1994 U.S. Senate election in Massachusetts, losing to long-time incumbent Ted Kennedy. In 1999, he was hired as President and CEO of the Salt Lake Organizing Committee for the 2002 Winter Olympics and Paralympics; and he helped turn the fiscally troubled games into a success.

Donald John Trump, Sr. (born June 14, 1946) is an American business magnate, television personality and author. He is the chairman and president of The Trump Organization and the founder of Trump Entertainment Resorts. Trump's extravagant lifestyle, outspoken manner and role on the NBC reality show The Apprentice have made him a well-known celebrity who was No. 17 on the 2011 Forbes Celebrity 100 list. He is well-known as a real-estate developer who amassed vast hotel, casino, and other real-estate properties, in the New York City area and around the world.

Trump is the son of Fred Trump, a wealthy New York City real-estate developer. He worked for his father's firm, Elizabeth Trump & Son, while attending the Wharton School of the University of Pennsylvania, and in 1968 officially joined the company. He was given control of the company in 1971 and renamed it The Trump Organization.

In 2010, Trump expressed an interest in becoming a candidate for President of the United States in the 2012 election. In May 2011, he announced he would not be a candidate, but a few weeks later he said he had not completely ruled out the possibility. In December 2011, Trump was suggested as a possible Vice Presidential selection by Michele Bachmann. Bachmann has since suspended her presidential campaign.