# Frequency, Cumulative Frequency, & Histograms

## Frequency and Cumulative Frequency

In the first video, we are going to use frequency and cumulative frequency.

For example:
List: 3, 3, 3, 9, 12, 14, 14, 15, 19, 29, 34, 34, 35, 36, 37

Let’s make a table to group the numbers. Make sure that the intervals are the same for all groups.

Frequency

 Range Tally Frequency $0 ||| 3 $5 | 1 $10 |||| 4 $15 | 1 $20 0 0 $25 | 1 $30 ||| 3 $35 || 2

Cumulative frequency starts from the first value, and the initial value remains when moving on to the next group.

For example:

 Range Tally Frequency $0 ||| 3 $0 |||| 4 $0 |||| ||| 8 $0 |||| |||| 9 $0 |||| |||| 9 $0 |||| |||| 10 $0 |||| |||| ||| 13 $0 |||| |||| |||| 15

## Representing Frequency and Cumulative Frequency with a Histogram

In the second video, we are going to create histogram.

Histogram:
Let’s use the same list from the first video. Histograms look relatively close to bar graphs with minor changes, but the overall ideas are the same. Mark the x-axis with the desired intervals and the y-axis with the values. Make sure that the values are increasing at a constant rate.

For the cumulative frequency, each interval of the histogram is going to be the sum from the first interval to the current interval as shown below: