This document defines and provides examples to calculate range, mode, median, and mean. It explains that to calculate these measures, the data set must first be arranged in ascending order. Range is the difference between the highest and lowest values, measuring dispersion. Mode is the most frequent value. Median is the middle value of an ordered data set. For an even number of values, the median is the average of the two middle values. Mean is the sum of all values divided by the total number of values, being the most widely used measure of central tendency. An example problem demonstrates calculating all four measures for a sample data set.