Comparing Distributions Diagram

Which type of frequency diagram is most useful when comparing two or more distributions plotted on the same axes?

Correct Answer Explanation

Frequency polygon is likely to be more useful when comparing two or more distributions plotted on the same axes.

Key Points:

• In histograms, the vertical and horizontal lines of two distributions may coincide, making comparison difficult.
• Frequency polygons use lines that can be easily distinguished even when overlapping.
• Multiple frequency polygons can be drawn on the same graph without confusion.
• Different colours or line styles can be used for different distributions.

Why Other Options Are Wrong

• A. Histogram: Rectangles of two histograms overlap and are hard to distinguish.
• C. Ogive: Ogive shows cumulative frequencies, not direct distribution comparison.
• D. Pie diagram: Pie charts cannot be overlaid for comparison on same axes.