This document defines and describes various measures of central tendency and variation that are used to summarize and describe sets of data. It discusses the mean, median, mode, midrange, percentiles, quartiles, range, variance, standard deviation, interquartile range, coefficient of variation, measures of skewness and kurtosis. Examples are provided to demonstrate how to compute and interpret these statistical measures.

1. Descriptions of Data Measures of Central Tendency Definition: A Measure of Central Tendency has been defined as a statistic calculated from a set of observations or scores and designed to typify or represent that series. It is also defined as the tendency of the same observations or cases to cluster about a point, with either to an absolute value or to a frequency of occurrence; usually but not necessarily, about midway between the extreme high and the extreme low values in the distribution.