Question

What is the z-score of sample X, if `n = 256, mu= 88, St. Dev. =128, and mu_X =96`?

Answer 1

`z=-1`

Explanation:

Given -

`n=256`
`mu=88`
`sigma=128`
`mu_x=96`

Find Standard Error

`SE=sigma/sqrt(n)=128/sqrt256=128/16=8`

Fidn the `z` score

`z=(mu-mu_x)/(SE)=(88-96)/8=-8/8=-1`
`z=-1`