Consider a normal population with µ = 25 and σ = 8.0.
(A) Calculate the standard score for a value x of 22.
(B) Calculate the standard score for a randomly selected sample of 45 with = 22.
(C) Explain why the standard scores of 22 are different between A and B above

I figure solution to A. is 25 - 22 / 7 = 0.428 but I dont have any idea how to work out the rest, help?

Question

Consider a normal population with µ = 25 and σ = 8.0.
(A)    Calculate the standard score for a value x of 22.
(B)    Calculate the standard score for a randomly selected sample of 45 with  = 22.
(C)    Explain why the standard scores of 22 are different between A and B above

I figure solution to A. is 25 - 22 / 7 = 0.428 but I dont have any idea how to work out the rest, help?

kropot72 · Answer

(A)
$$z=\frac{X-\mu}{\sigma}=\frac{22-25}{8}=you\ can\ calculate$$