Which chart type is best for illustrating the distribution of numeric data across equal-width intervals?

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

Answer: (A)

A histogram is the best choice because it directly shows how many observations fall into each equal-width numeric interval, revealing the overall shape of the data—where values cluster, how spread out they are, any skew, and potential multiple peaks. The x-axis is the value range split into equal-sized bins, and the y-axis displays the frequency (or relative frequency) in each bin, making comparisons across intervals straightforward.

Bar charts are designed for discrete categories, not a continuous numeric range, so they don’t convey distribution across evenly spaced intervals. Pie charts show parts of a whole and aren’t suited to display frequencies across a continuum. Line charts emphasize changes over time or sequence, not the distribution of values across equal-width numeric bins.