Question

suppose your statistics professor reports test grades as z - scores, and you got a score of 2.20 on an exam. write a sentence explaining what that means. select the correct choice below.
a. the score was 2.20 standard deviations lower than the mean score in the class.
b. the score was 2.20 standard deviations higher than the mean score in the class.
c. the score was 2.20 points higher than the mean score in the class.
d. the score was 2.20 points lower than the mean score in the class.

Explanation:

Step1: Recall z - score concept

The z - score represents the number of standard deviations a data - point is from the mean. A positive z - score indicates that the data - point is above the mean, and a negative z - score indicates that the data - point is below the mean.

Step2: Analyze given z - score

The z - score is 2.20, which is positive. This means the score is 2.20 standard deviations higher than the mean score in the class.

Answer:

B. The score was 2.20 standard deviations higher than the mean score in the class.