In a population of scores,X = 83 corresponds to z = -0.50 and X = 93 corresponds to z = +2.00.What are the values for the population mean and standard deviation?
A)m = 85 and s = 4
B)m = 85 and s = 2
C)m = 81 and s = 4
D)m = 81 and s = 6

Question

In a population of scores,X = 83 corresponds to z = -0.50 and X = 93 corresponds to z = +2.00.What are the values for the population mean and standard deviation?​
A)m = 85 and s = 4​
B)​m = 85 and s = 2
C)​m = 81 and s = 4
D)​m = 81 and s = 6

Quizplus · Accepted Answer

The z-score formula is z = (X - m) / s, where X is the score, m is the mean, and s is the standard deviation. Using the given z-scores and X values, two equations can be set up: -0.50 = (83 - m) / s and 2.00 = (93 - m) / s. Solving these equations simultaneously gives m = 85 and s = 4.

In a Population of Scores,X = 83 Corresponds to Z