Question

A sample of n = 9 scores is obtained from a population with μ = 70 and σ = 18. If the sample mean is M = 76, 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

Answer: The Z-score for the sample mean is 1.00. So, the correct answer is c. z = 1.00.

Given:n = 9,μ = 70 and σ = 18.

Explanation To find the Z-score for the sample mean, you can use the formula:

Z = (Sample mean - Population mean) / (σ / √n)

where Population mean (μ) = 70, σ = 18, and n = 9.

Z = (76 - 70) / (18 / √9) = 6 / (18 / 3) = 6 / 6 = 1.00

The Z-score for the sample mean is 1.00. So, the correct answer is c. z = 1.00.