A sample of n 36 scores is selected from a population with

A sample of n = 36 scores is selected from a population with = 12. If the sample mean of M = 56 produces a z-score of z = +3.00, then what is the population mean?

Solution

As

z = (x-u) * sqrt(n) / sigma

Then

3.00 = (56-u)*sqrt(36)/12

6 = (56-u)

u = 50 [ANSWER]