Question

The Graduate Management Admission Test (GMAT) is a standardized exam used by many universities as part of the assessment for admission to graduate study in business. The average GMAT score is 547 (Magoosh website, January 5, 2015). Assume that GMAT scores are bell-shaped with a standard deviation of 100. Make sure to use the empirical rule to answer these questions. a. What percentage of GMAT scores are 647 or higher? %

Answer 1

16.7% of GMAT scores are 647 or higher

Explanation:

The Empirical Rule states that 68% of the values are within 1 standard deviation of the mean(34% above, 34% below). It also considers that 50% of the values are above the mean and 50% are below the mean.

In this problem, we have that the mean
`\mu` is 547 and that the standard deviation
`\sigma` is 100.

a. What percentage of GMAT scores are 647 or higher?

647 is 1 standard deviation above the mean.

So, 50% of the values are below the mean. Those scores are lower than 647.

Also, there is the 34% of the values that are above the mean and are lower than 647.

So, there is a 50% + 34% = 84% percentage of GMAT scores that are 647 or lower.

The sum of the probabilities must be 100

So, the percentage of GMAT scores that are 647 or higher is 100% - 84% = 16%.