Question

What is the z-score of sample X, if `n = 9, mu= 56, SD =30, and E[X] =32`?

Answer 1

The answer is `=2.4`

Explanation:

The z-score for a sample mean is

`z=(barx-mu)/(sigma/sqrt9)`

`barx= E[X]=32`

`mu=56`

`sigma=30`

`n=9`

Therefore,

`z=(32-56)/(30/sqrt9)=-24/10=-2.4`