If a distribution of scores has a mean of 60 and a standard deviation of 10, then a score of 50 has a z score that is _____ standard deviation(s) _____ the mean.
A) 2; below
B) 1; above
C) 1; below
D) 2; above

Question

Quizplus · Accepted Answer

To find the z-score, we use the formula z = (X - μ) / σ, where X is the score of interest, μ is the mean, and σ is the standard deviation. Plugging in the values, we get z = (50 - 60) / 10 = -1. This means the score of 50 is 1 standard deviation below the mean. Therefore, the correct choice is C.

If a Distribution of Scores Has a Mean of 60