Question

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

Answer 1

Do Correct sum - correct mean ur answer will come.

Answer 2

Wrong mean :-
Sup the terms are in x forms,
x1 + x2 +.......+x39 + 53
__________________ = 38
40
= x1 + x2 +.......+x39 + 53 = 38×40
= x1 + x2 +.......+x39 = (38×40)-53
Original mean :-
= x1 + x2 +.......+x39 + 35
_____________________ = ?
40

= (38×40)-53 + 35
_________________
40
= (38×40)-18
____________ = 37.55
40

Therefore the ans. is 37.55