A cumulative frequency table is a type of frequency distribution that shows the total number of observations that fall below or at a certain class boundary. It helps in understanding how data accumulates over different class intervals.
Structure of a Cumulative Frequency Table
A cumulative frequency table typically consists of the following columns:
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Class Intervals – The range of data grouped into classes.
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Frequency (f) – The number of observations in each class.
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Cumulative Frequency (CF) – The running total of frequencies, adding up as you move from the first class to the last.
Example of a Cumulative Frequency Table
| Class Interval | Frequency (f) | Cumulative Frequency (CF) |
|---|---|---|
| 0 – 10 | 5 | 5 |
| 10 – 20 | 8 | 5 + 8 = 13 |
| 20 – 30 | 12 | 13 + 12 = 25 |
| 30 – 40 | 10 | 25 + 10 = 35 |
| 40 – 50 | 15 | 35 + 15 = 50 |
Uses of Cumulative Frequency Tables:
✔ Used to create cumulative frequency graphs (ogives)
✔ Helps in finding median, quartiles, and percentiles
✔ Useful for analyzing data distribution patterns