Two or more frequency polygons can be overlaid on the same axes for easy comparison (e.g., boys vs. girls, pre-test vs. post-test). 5. Relative Frequency Polygon When comparing datasets of different sizes, use relative frequencies:
[ \textRelative frequency = \frac\textClass frequency\textTotal sample size ] frekans poligonu
| Class Interval | Frequency (f) | |----------------|---------------| | 30 – 40 | 4 | | 40 – 50 | 6 | | 50 – 60 | 12 | | 60 – 70 | 18 | | 70 – 80 | 8 | | 80 – 90 | 2 | Two or more frequency polygons can be overlaid
| Midpoint | Rel. Freq A | Rel. Freq B | |----------|-------------|-------------| | 35 | 0.08 | 0.10 | | 45 | 0.12 | 0.13 | | 55 | 0.24 | 0.20 | | 65 | 0.36 | 0.27 | | 75 | 0.16 | 0.20 | | 85 | 0.04 | 0.10 | Freq B | |----------|-------------|-------------| | 35 | 0
The shape remains identical to the raw frequency polygon, but the y-axis scale changes to proportions (0 to 1) or percentages (0 to 100%). This normalization allows fair visual comparison. Scores of Group A (n=50) and Group B (n=30) – relative frequencies:
