ABSTRACT
This chapter describes the measures of central tendency that are frequently used by researchers. There are detailed descriptions of the mean, the median, and the mode. These descriptions include definitions of each of these central tendency statistics, how to calculate each one, the symbols used for each, and how these symbols differ for sample and population data. In addition, the chapter includes a discussion of how different shapes of distributions affect the mean, median, and mode. The chapter includes information about skewed distributions and how outliers can affect the shape of the distribution, the mean, and, to a lesser extent, the median. Examples of how outliers affect the shape of distributions are offered for mean and median wealth in the San Francisco Bay Area and life expectancy in several different countries.
