A sample of n = 9 scores is obtained from a population with μ = 70 and σ = 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

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,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

Quizplus · Accepted Answer

To find the z-score for the sample mean, we use the formula:

z = (M - μ) / (σ / √n)

Substituting the given values, we get:

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

Therefore, the z-score for the sample mean is z = 1.00, which corresponds to choice C.

A Sample of N = 9 Scores Is Obtained from a Population