A testing bureau reports that the mean for the population of Graduate Record Exam (GRE) scores is 500 with a standard deviation of 90. The scores are normally distributed. The raw score that lies at the 90th percentile is _________.
A) 615.20
B) 384.80
C) 616.10
D) 383.90

Question

Quizplus · Accepted Answer

To find the raw score at the 90th percentile, we use the z-score for the 90th percentile, which is approximately 1.28. The formula to find the raw score is: raw score = mean + (z-score * standard deviation). So, 500 + (1.28 * 90) = 615.20.

A Testing Bureau Reports That the Mean for the Population