The mean of 50 observations was 250. later it was found that the number 152 was wrongly copied as 102 for the computation of means. find the correct mean.
Dear student,
Here, we have
No. of observation, N = 50
Here, we have
No. of observation, N = 50
Incorrect Mean = 250
Right item = 152
Wrong item = 102
As we know that
Mean = Sum of observation ( X )/ No. of observation
250 = X /50
X = 12,500
Hence sum of observation is 12,500
Now
Correct sum of observation = 12500 - Wrong item + Correct item
= 12500 - 102 + 152
= 12, 550
Now correct Mean
Mean = 12550/ 50
= 251
Hence the correct Mean = 251