Question

what is index number

Answer 1

Index number is the power of number.
for example,
${2}^{2}$
Here,index number or power of the number is 2.
Hope it helps you!

Answer 2

Hello friend! Thanks for asking question, here is the answer.

Index numbers are meant to study changes in the effects of factors which cannot be measured directly.

I hope this will help you. Thank you.