If a variable is normally distributed with a mean of 30 and a standard deviation of 6, approximately ______ of the scores are between ______and ______.
A) 68%; 24 and 36
B) 95%; 6 and 54
C) 68%; 12 and 48
D) 99%; 24 and 36

Question

Quizplus · Accepted Answer

This is a standard normal distribution, and we can use the empirical rule. Approximately 68% of the scores fall within one standard deviation of the mean in either direction. Therefore, approximately 68% of scores are between (30-6) = 24 and (30+6) = 36.

If a Variable Is Normally Distributed with a Mean of 30