Question

The average mean of 18 boys is 40. Later it was found that a weight was incorrectly read as 35 kg and correct was 53 kg then average mean was?

Answer 1

answer in attachment

Answer 2

Mean of 18 boys =40

Mean = sum of observation / no of observation

40 =sum of observation /18

Sum of observation = 18×40

sum of observation = 720

A/Q

35 kg is 53

So,

Now sum of observation =720-35+53

sum of observation = 738

New mean = 738÷18

New mean =41