An index number is a statistical measure designed to show changes in variables or a group of

related variables with respect to time, geographic location of other characteristics. Explain.

After the study of above definition, we can explain the following features/characteristics of index

number

(i) Index number are specialised average and not simple average.

(ii) These number are expressed in terms of percentage.

(iii) These number measure the net change in a group of related variables over a period of time.