Frequency of a class divided by total frequency of all classes is called relative frequency. Relative frequency is expressed in terms of percentage therefore it is also known as percentage distribution. A table showing intervals with corresponding relative frequencies is called a relative frequency distribution. The concept of relative frequency distribution can be explained with the help of following table.
In the above table, frequencies given in the second column are called class frequencies. These frequencies can be converted into proportions by dividing each class frequency by total of frequencies. For example in the above table class frequency of first class interval is 6 and its relative frequency is 0.06 (6/100).