The mean of 150 items was found to be 60. Later on, it was discovered that the values of two items were misread as 52 and 8 instead of 152 and 88 respectively.

Question:

The mean of 150 items was found to be 60. Later on, it was discovered that the values of two items were misread as 52 and 8 instead of 152 and 88 respectively. Find the correct men.

Solution:

Mean of 150 items = 60

Sum of 150 items $=(150 \times 60)=9000$

New sum $=[9000-(52+8)+(152+88)]=9180$

Correct mean $=\frac{\text { New sum }}{\text { Total items }}=\frac{9180}{150}=61.2$

Therefore, the correct mean is $61.2$.

 

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