Question

What is the z-score of sample X, if `n = 400, mu= 41, St. Dev. =65, and E[X] =31`?

Answer 1

`z=(-40)/13=-3.076923077`

Explanation:

Given data:

`x=31`
`mu=41`
`sigma=65`
`n=400`

The formula

`z=(x-mu)/((sigma/sqrtn))`

`z=(31-41)/((65/sqrt400))`

`z=-40/13`

God bless....I hope the explanation is useful.