Pie graphs are most useful when dealing with cross-section data where one's primary concern is with showing distribution-the parts of a whole. If you are doing a pie graph you MUST be graphing something which when you add up all of the pieces, the whole is something meaningful. For example, you could look at your finances and construct a pie graph that shows how much of your total spending is on food, clothing, recreation, education, and transportation. In the example below, we have a pie graph of regional population shares in the United States in 1990. New England and the Mountain regions had the smallest populations, each with 5 percent of the nation's population while the East North Central and South Atlantic regions were the largest with 18 percent. What we can not determine from the graph is the level of population. If we wanted to show the level of population, we would need to use another type of graph. One possibility would be a stack graph, a variation on the column/bar graph.