The Geometric Index or Industrial Share index
The Geometric Index or Industrial Share index is an index of 30 selected top industrial companies. This is calculated by taking an un-weighted geometric mean of the price relatives of the chosen shares.
The share prices of ordinary shares of four companies on date 1st January 1990 and on date 1st January 1991 were given as.
Price on 1.1.1990
Price on 1.1.1991