Question

Scores on the GRE (Graduate Record Examination) are normally distributed with a mean of 579 and a standard deviation of 94. Use the 68-95-99.7 Rule to find
the percentage of people taking the test who score between 391 and 767
The percentage of people taking the test who score between 391 and 767 is
%.

Answer 1

Answer:

The percentage of people taking the test who score between 391 and 767 is 95%.

Step-by-step explanation:

The Empirical Rule(68-95-99.7 Rule) states that, for a normally distributed random variable:

68% of the measures are within 1 standard deviation of the mean.

95% of the measures are within 2 standard deviation of the mean.

99.7% of the measures are within 3 standard deviations of the mean.

In this problem, we have that:

Mean = 579

Standard deviation = 94

391 = 579 - 2*94

So 391 is two standard deviations below the mean.

767 = 579 + 2*94

So 767 is two standard deviations above the mean.

By the Empirical Rule:

The percentage of people taking the test who score between 391 and 767 is 95%.