This document discusses calculating measures of central tendency (mean, median, mode) from individual series, discrete series, and continuous series data. It provides examples of calculating the mean, median, and mode from various data sets, including individual data points, frequency distributions, and grouped data. The mean is calculated by summing all values and dividing by the total number of data points. The median is found by ordering the data and taking the middle value. The mode is the value that occurs most frequently for individual data and the class with the highest frequency for continuous data.