Which chart type best represents proportions of categories?

• A. Bar chart
• B. Pie chart
• C. Line graph
• D. Histogram

Answer: (B)

When you want to show how a whole is divided among different categories, you need a chart that encodes proportions directly. A pie chart does that by dividing a circle into slices where each slice’s size (angle or area) corresponds to the category’s share of the total. This makes it easy to compare how big each part is relative to the whole and to spot which categories dominate or are small.

Bar charts compare category values side by side, which is great for comparing amounts, but they don’t inherently show each part’s relationship to the total. Line graphs track changes over time rather than how a whole is partitioned. Histograms reveal the distribution of a continuous variable, not proportions of discrete categories.

So, for illustrating proportions of categories, the pie chart is the most direct and intuitive choice.