Question

Applicants to a college psychology department have normally distributed GRE (Graduate Record Exam) scores with a mean of 544 and a standard deviation of 103. What is the GRE score at the 77th percentile? Round answer to the nearest whole number.
A. 620
B.505
C.468
D.1
E.-1
not really sure how to do this problem, i did it two different ways and got two different answers and both those answers weren't a choice. Someone please help me walk through the steps if you know the answer :)

Answer 1

The first step is use a table to find how many standard deviations (above the mean) correspond to 0.77
Do you know how to do that ?

Answer 2

As you know, the area under the bell curve from the "left tail" up to the mean is 1/2 of the total area. In other words, 0.5 of the area is below 544

Answer 3

77% or 0.77 means we want the score where 0.77 of the total area is below that score.

common sense says that this score must be bigger than the mean 544
so we can answer the question by process of elimination: only 1 of your choices works.