Cumulative frequency is used to calculate:

Cumulative frequency is used to calculate the total number of observations that fall below the upper boundary of a particular category or interval in a dataset. It is a running total of frequencies.

Here are the steps to calculate cumulative frequency:

1. Organize your data in ascending order: This is important because cumulative frequency builds upon an ongoing total.

2. Tally the frequency of each category or interval: This is your basic frequency distribution, showing how often each category or interval occurs.

3. Add the frequency of the current category or interval to the sum of the frequencies of all previous categories or intervals: This is your cumulative frequency. For the first category or interval, the cumulative frequency will be the same as the regular frequency. For each subsequent category or interval, add the regular frequency to the cumulative frequency of the previous category or interval.

4. Repeat step 3 for all categories or intervals: This will give you the cumulative frequency for each category or interval.

5. The final cumulative frequency should be equal to the total number of observations in your dataset.

Cumulative frequency is often used in statistical analysis and data presentation. It can be used to create a cumulative frequency distribution or an ogive (a type of frequency polygon), which can help visualize the cumulative frequencies of the categories or intervals.