question_answer

In an experiment with 15 observations on x, the following results were available \[\sum {{x}^{2}}=2830,\,\,\sum x=170\]. One observation that was 20, was found to be wrong and was replaced by the correct value 30. Then, the corrected variance is     AIEEE  Solved  Paper-2003

A) 78.00             

B)       188.66                  

C)       177.33            

D)                       8.33

Correct Answer: A

Solution :

                Variance Given, N = 15                        One observation 20 was replaced by 30, then                                 Variance,