Question

What is the z-score of sample X, if `n = 49, mu= 75, SD =42, and E[X] =88`?

Answer 1

The z-score `=13/6`

Explanation:

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

`barx=88`
`mu=75`
`sigma=42`
`n=49`

`:.` z-score `=(88-75)/(42/sqrt49)=13/(42/7)=13/6`