This document discusses stem-and-leaf plots and different measures of central tendency including mean, median, and mode. A stem-and-leaf plot arranges data by grouping numbers with the same stem. The mean is found by adding all the numbers and dividing by the total numbers. The median is the middle number when the data is ordered. The mode is the number that occurs most frequently and data can have no mode or more than one mode. Examples are provided to calculate and interpret the mean, median, and mode of sample data sets.