Answer:
16.7% of GMAT scores are 647 or higher
Step-by-step 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 [tex]\mu[/tex] is 547 and that the standard deviation [tex]\sigma[/tex] 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%.