Question

the average weight of group of 25 boys was calculated to be 52 kg it was later discovered that the weight of a boy was wrongly read as 45kg instead of 54 kg . what is the correct average weight

Answer 1

Answer: The correct average weight is 52.36 kg

Explanation: Total number of boys (n) = 25

Calculated average weight (X) = 52

Since X is arithmetic mean so,

X = ∑X/n

or ∑X = n*X

= 25*52 = 1300

But this is not the correct ∑X

Therefore, Correct ∑X = 1300 - (Wrong entries) + (Right entries)

= 1300-45+54 = 1309

Hence, Correct X = 1309/25 = 52.36

Hope this helps!