Scores on a test have a mean of 66 and a standard deviation of 9. Michelle has a score of 57. Convert Michelle's score to a z score.
A) 1
B) -1
C) -9
D) 9

Question

Quizplus · Accepted Answer

To convert to a z-score, we use the formula:

z = (x - μ) / σ

where
x = the score we want to convert
μ = the mean
σ = the standard deviation

Plugging in the values, we get:

z = (57 - 66) / 9 = -1

Therefore, Michelle's score of 57 has a z-score of -1.

Scores on a Test Have a Mean of 66 and a Standard