Question

What is the first error he made in computing the standard deviation?

A.Yuri failed to find the difference between each data point and the mean.

B.Yuri divided by n instead of n -1.

C.Yuri did not subtract 9 - 14 correctly.

D.Yuri failed to square -2 correctly.

Answer 1

b.yuri divided by n instead of n-1

Answer 2

Explanation:

Given is a sample with 4 items as

12,9,14,21

Mean = average of 4 = 14

s is the square root of sample variance

Sample variance is the sum of squares divided by n-1

But Yuri divided by 4 = n instead of 3 = n-1

That is the only mistake he did and all other steps are right.