If a distribution is normally shaped with a μ = 40 and a σ_M = 4, what is p(M

Question

If a distribution is normally shaped with a μ = 40 and a σ_M = 4, what is p(M < 38)? A) .6915 B) .3085 C) .8413 D) .1587

Quizplus · Accepted Answer

To find the probability of M being less than 38, we need to standardize the value of 38 with respect to the given mean and standard deviation.

z = (38-40)/4 = -0.5

From the standard normal distribution table, the probability of getting a z-score less than -0.5 is 0.3085. Therefore, the answer is B.

If a Distribution Is Normally Shaped with a μ =