This document defines and provides examples for calculating the mean, median, mode, and range of a data set. It explains that the mean is the average found by adding all values and dividing by the number of values. The median is the middle number after arranging the data from lowest to highest. The mode is the value that occurs most frequently. The range is the difference between the highest and lowest values. It provides step-by-step instructions and examples for calculating each of these measures of central tendency and spread.