A stem and leaf graph is used to plot the frequency distribution of a data set. By rotating a stem and leaf graph 90 degrees counterclockwise, you can get a plot that resembles a bar graph or histogram. Stem and leaf graphs are often better than the bar graph or histogram because all the original data values are displayed.

The stem and leaf graph enables you to locate clusters, gaps, largest and smallest values, outliers, the relative position of any item important to you, and the general shape of the distribution. In addition, a back-to-back stem and leaf graph lets you compare two sets of data.

This back-to-back stem and leaf graph displays the number of buildings above 400 feet in Los Angeles and San Francisco. Before making comparisons with a back-to-back stem and leaf graph, first check to ensure that both sets have about the same total number of values. Keep in mind that stem and leaf graphs are best used when there are more than 25 pieces of data. The stem and leaf graph is often used as a substitute for the less informative histogram and bar graph.