Mean of 9 numbers was found to be 89. Later on it was detected that one number 81 was misread as 18 . Find the correct mean.

Given:

Mean of 9 numbers was found to be 89.

Later on it was detected that one number 81 was misread as 18.

To find: Here we have to find the correct mean.

Solution:

Mean of 9 observations = 89

Sum of 9 observations = 89 $\times$ 9

Sum of 9 observations = 801

Since one observation 81 was misread as 18.

Then,

New sum of observations = 801 $-$ (Wrong observation) $+$ (correct observation)

New sum of observations = 801 $-$ 18 $+$ 81 = 864

The correct mean = $\frac{New\ sum\ observations}{Total number of observations}$

The correct mean = $\frac{864}{9}$

The correct mean = 96

So, the correct mean is 96.

Tutorialspoint

Simply Easy Learning

Updated on: 10-Oct-2022

203 Views

Kickstart Your Career

Get certified by completing the course

Get Started