Question

What is the z-score of sample X, if `n = 144, mu= 41, St. Dev. =120, and E[X] =63`?

Answer 1

The z-score is `=2.2`

Explanation:

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

`=(63-41)/(120/sqrt144)=22/(120/12)=22/10=2.2`