What does a pie chart illustrate?

• A. The relationship of parts to a whole, often represented as percentages of a total
• B. The frequency of categorized data points within defined ranges
• C. The changes over time
• D. The arrangement of bars in a chart

Answer: (A)

Pie charts show how a whole is divided among parts; each slice represents a portion of the total, usually shown as a percentage. This makes it easy to see which categories dominate the total and how the total is distributed across parts. They’re best when you have a small number of categories and want to highlight composition, such as market share by category. They aren’t meant for showing how often data occur across ranges, how values change over time, or the sequence of bars—those are better shown with bar charts, line charts, or histograms depending on the case.