Graduate Record Examination

Question

Scores on the GRE​ (Graduate Record​ Examination) are normally distributed with a mean of 550 and a standard deviation of 115. Use the 65-95-99.7 Rule to find the percentage of people taking the test who score between 205 and 550

What is the percentage of students who score between 205 and 550?

Answer 1

How far is 205 from 550? 550 - 205 = 345. How many standard deviations is that? 345/115 = 3. 205 is 3 standard deviations away from 550 on the lower side.

Per empirical rule 99.7 percent of data is within 3 standard deviations of the mean on both sides, so 99.7/2 = 49.85 percent of the data is within 3 standard deviations on one side of the mean.