Question

What is the z-score of sample X, if `n = 121, mu= 23, St. Dev. =110, and E[X] =43`?

Answer 1

The z-score is `=2`

Explanation:

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

`=(43-23)/(110/sqrt121)=20/(110/11)=20/10=2`