During July 2005, the seven most-visited shopping websites (with number of visitors, in millions) were: eBay (61.7), Amazon (42.0), Wal-Mart (22.6), Shopping.com (22.4), Target (20.5), Apple Computer (17.4), and Overstock.com (17.2). Considering these as a population, determine: Source: The World Almanac and Book of Facts 2006, p. 390.
a. The mean, median, range, and midrange.
b. The mean absolute deviation.
c. The standard deviation and variance.