Question

the mean of 30 observations was calculated as 150. later, it was pointed out that value of one of the observations was wrongly taken as 135 instead of 165. the correct mean is

Answer 1

Answer:

151.34

Step-by-step explanation:

Given the mean of 30 observations is 150.

We know that, Mean= Sum of all the observations/total no. of observations

So, here, 150=Sum of all the observations/30

=>Sum of all the observations=30*150=4500

Now given that one observation was wrongly taken as 135 instead of 165,thus taking the correct observation, the total sum of 30 observations will now be equal to:4500-135+165=4540

Thus, the correct mean=total sum after correction/30=4540/30=151.34