Caddell Prep Access Menu

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<n\leq5 ||| 3
5<n\leq10 | 1
10<n\leq15 |||| 4
15<n\leq20 | 1
20<n\leq25 0 0
25<n\leq30 | 1
30<n\leq35 ||| 3
35<n\leq40 || 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<n\leq5 ||| 3
0<n\leq10 |||| 4
0<n\leq15 |||| ||| 8
0<n\leq20 |||| |||| 9
0<n\leq25 |||| |||| 9
0<n\leq30 |||| |||| 10
0<n\leq35 |||| |||| ||| 13
0<n\leq40 |||| |||| |||| 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.

histogram frequency

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:
histogram cumulative frequency