Question

A sample of n = 9 scores is obtained from a population with ƒÝ = 70 and ƒã = 18. If the sample mean is M = 76, then what is the z-score for the sample mean?
a. z = 0.33
b. z = 0.50
c. z = 1.00
d. z = 3.00

Answer 1

Formula:
z = (x - mean)/(sd/√n)

With your data:
z = (76 - 70)/(18/√9) = 6/6 = 1

Choice: c

Answer 2

Thank you for the help.