Displaying Distributions With Graphs. Section 1.1. A Picture is worth a thousand words. First three rules for describing data: Make a picture Make a picture Make a picture. Categorical Data.
Bar Graphs show a bar that represents either the count, proportion, or percentage of each category. Bar graphs may or may not show all categories.
Pie Graphs show how a “whole” divides into categories using either the proportion or percentage. To use a pie graph you must include all the categories that make up the whole.