Frequency Polygon
A frequency polygon is a line graph that represents a frequency distribution. It connects midpoints of class intervals with straight lines.
Key Features of a Frequency Polygon:
✔ It is created by plotting points at class midpoints and connecting them.
✔ The x-axis represents class midpoints, and the y-axis represents frequency.
✔ Can be used to compare multiple distributions on the same graph.
Example: Frequency Polygon for Student Test Scores
| Class Interval (Marks) | Midpoint | Frequency (f) |
|---|---|---|
| 0 – 10 | 5 | 5 |
| 10 – 20 | 15 | 8 |
| 20 – 30 | 25 | 12 |
| 30 – 40 | 35 | 10 |
| 40 – 50 | 45 | 15 |
🔹 Graph Interpretation:
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The highest peak represents the most frequent category.
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A smooth curve can be drawn for better visualization.
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It helps in comparison between datasets.