Question

given that a set of scores have a normal distribution, a mean of 54, and a standard deviation of 3: what is the range within three standard deviations of the mean? 52 - 55 51 - 57 48 - 60 45 - 63

Explanation:

Step1: Calculate lower - bound

$54-3\times3 = 45$

Step2: Calculate upper - bound

$54 + 3\times3=63$

Answer:

D. 45 - 63