Question

What is the z-score of sample X, if `n = 169, mu= 42, St. Dev. =39, and E[X] =12`?

Answer 1

The z-score is`=-10`

Explanation:

The z-score for a sample mean is `(barx-mu)/(sigma/sqrtn)`

So, here we have `=(12-42)/(39/sqrt169)`

`=-30/(3)=-10`