A random variable is normally distributed with a mean of -50 and a standard deviation of 10. If an observation is randomly selected from the distribution, what value will be exceeded 85% of the time?
A) -60.34
B) 60.34
C) -39.66
D) 39.66

Question

Quizplus · Accepted Answer

To find the value that will be exceeded 85% of the time, we need to find the 15th percentile of the distribution. Using the Z-table, the Z-score for 0.15 is approximately -1.04. Using the formula X = μ + Zσ, where μ = -50 and σ = 10, we get X = -50 + (-1.04)(10) = -39.66.

A Random Variable Is Normally Distributed with a Mean of -50