What is the difference between frequency and cumulative frequency.
cumulative frequency: it is used to determine the number of observations that lie below a particular value in a data set.
the cumulative frequency is calculated by adding each frequency from a frequency distribution table to the sum of its predecessors. the last value will always be equal to the total for all observations.
the following table represent the marks obtained by a class of 40 students out of 50.
there are 3 students , who scored marks less than 10.
8 students scored marks less than 20. so cumulative frequency is 11.
thus 11 students scored marks less than 20.
| class Interval | frequency | cumulative frequency |
| 0-10 | 3 | 3 |
| 10-20 | 8 | 11 |
| 20-30 | 12 | 23 |
| 30-40 | 12 | 35 |
| 40-50 | 5 | 40 |
hope this helps you.
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