Question

What is the z-score of sample X, if `n = 256, mu= 42, St. Dev. =80, and mu_X =89`?

Answer 1

`z=47/5=9.4`

Explanation:

Use the formula

`z=(mu_x-mu)/((sigma/sqrtn))=(89-42)/((80/sqrt(256)))=47/((80/16))=47/5`

`z=9.4`

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