Cumulative Frequency

It all adds up…

Cumulative Frequency

Cumulative means totalling or gradually building up. In statistics, cumulative frequencyis found by adding up all successive frequencies in a frequency distribution table.

Cumulative Frequency

Below is a frequency distribution table that shows the hours of sleep on a school night by 98 Year 8 students (from the ABS website).

Hours of Sleep Frequency

6 10

7 7

8 22

9 31

10 21

11 4

12 2

13 1

Cumulative Frequency

10

17

39

70

91

95

97

98

Cumulative Frequency

A cumulative frequency histogram is like a frequency histogram but uses the cumulative frequency column to graph the data. It looks like steps going upwards.

An ogive is a line graph drawn on the cumulative frequency histogram. The line starts at the bottom left corner of the first column and joins the top right corner of each successive column.

Tick marks every 1cm, mark scale 2cm=10

Tick marks every 2 cm, mark scale at each tick mark: 6 - 13