Question

The mean of 100 observations are 50. The value of the largest observation is 100. It was later

found that it is 110 not 100. Find the correct mean.​

Answer 1

We know that Arithmetic mean =∑X/N

Given Mean =50

N=100

i.e, 50= 100 ∑X

∑X=5000

Later found that it is 110

So the 100 items is wrong value

correct A.M = [∑X (wrong) + correct value of observation −

Incorrect value of observation]/N

correct Mean =[5000+110−100]/100

=[5110−100]/100

= $\frac{5010}{100}$

=50.10

∴ The real or true mean value is 50.10

Median value is 52