The mean of 40 observations was 160.It was detected on rechecking that the value of 165 was wrongly copied as 125 for computation of mean.Find the correct mean.

Asked by anusarika mohanty | 30th Dec, 2013, 08:28: PM

Expert Answer:

We know that:
Mean = sum of alll observations / number of observations
 
So, 160 = Sum /40
Sum = 6400
 
Now, correct sum = incorrect sum - incorrect value + correct value
                        = 6400 - 125 + 165
                        = 6440
 
Thus, correct mean = correct sum/ number of observations = 6440/40 = 161

Answered by  | 30th Dec, 2013, 10:18: PM

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