The cumulative frequency divided by the total frequency is called relative cumulative frequency or percentage cumulative frequency. It is used to know the percentage of observations falling below a certain specified value. A table showing relative cumulative frequencies instead of cumulative frequencies is called relative cumulative frequency distribution. The concept of relative cumulative frequency distribution can be explained with the help of following figure.
In the above figure relative cumulative frequencies (R.C.F) is calculated by dividing the cumulative frequency (C.F) by total frequency. For example R.C.F of “less than 11.5 is calculated by dividing 6 by 100 and multiplying by 100 (6/100 = 0.06 * 100 = 6%). Here 100 is total frequency of all observations. Now this R.C.F of 6% shows that about 6% observations fall below 11.5.