Question

what is index number ?​

Answer 1

it is the quantity or price compared with standard value

Answer 2

A simple index number is the ratio of two values representing the same variable, measured in two different situations or in two different periods. For example, a simple index number of price will give the relative variation of the price between the current period and a reference period.

To calculate the percent change between two non-base index numbers, subtract the second index from the first, divide the result by the first index and then multiply by 100.