Question

the mean of 40 number was found to be 38 later on it was detected that a number 35 wa misread as 53 . find the correct mean of given number

Answer 1

Mean of 40 = 38
Sum total = 40*38 = 1520

'35' was misread as '53'
Hence actual sum = 1520 - 53 + 35 = 1502

Correct mean = 1502/40 = 37.55

OR

Correct mean = Mean + (change in value)/number of readings
= 38 + 35-53/40 = 38 - 0.45 = 37.55