How to calculate cumulative frequency?

To calculate cumulative frequency, follow these steps:

1. Organize your data in ascending order.
2. Create a table with two columns: one for the data values and one for the cumulative frequency.
3. Start with the first data value and count how many times it appears in the data set. This is the frequency of that data value.
4. Write this frequency in the cumulative frequency column next to the corresponding data value.
5. Move on to the next data value and add its frequency to the cumulative frequency of the previous data value.
6. Continue this process for each data value, adding the frequency of each value to the cumulative frequency of the previous value.
7. The final cumulative frequency should be equal to the total number of data points in the data set.

Alternatively, you can use the following formula to calculate cumulative frequency:

Cumulative Frequency = Previous Cumulative Frequency + Frequency of Current Data Value

By following these steps or using the formula, you can easily calculate the cumulative frequency of a data set.

Steps to Calculate Cumulative Frequency:

1. Create a Frequency Table:
- Organize the data into a table, with intervals and frequencies for each interval.

2. Calculate Frequency for Each Interval:
- Count the number of data points that fall within each interval.

3. Calculate Cumulative Frequency:
- Start with the lowest interval and add the frequencies for each subsequent interval.

Formula for Cumulative Frequency:

```
Cumulative Frequency (CF) = Frequency of Current Interval + Frequency of Lower Intervals
```

Example:

Suppose we have the following frequency table:

| Interval | Frequency |
|---|---|
| 0-10 | 5 |
| 10-20 | 10 |
| 20-30 | 15 |
| 30-40 | 20 |

Calculating Cumulative Frequency:

- CF for 0-10 = 5 (Frequency of 0-10)
- CF for 10-20 = 5 + 10 = 15 (Frequency of 10-20 + CF for 0-10)
- CF for 20-30 = 15 + 15 = 30 (Frequency of 20-30 + CF for 10-20)
- CF for 30-40 = 30 + 20 = 50 (Frequency of 30-40 + CF for 20-30)

Result:

| Interval | Frequency | Cumulative Frequency |
|---|---|---|
| 0-10 | 5 | 5 |
| 10-20 | 10 | 15 |
| 20-30 | 15 | 30 |
| 30-40 | 20 | 50 |