Professors at a local university earn an average salary of $80,000 with a standard deviation of $6,000. The salary distribution is approximately bell-shaped. What can be said about the percentage of salaries that are less than $68,000 or more than $92,000?
A) It is about 5%.
B) It is about 32%.
C) It is about 68%.
D) It is about 95%.

Question

Quizplus · Accepted Answer

According to the empirical rule (68-95-99.7 rule) for a bell-shaped distribution, approximately 95% of the data falls within two standard deviations of the mean. Since $68,000 and $92,000 are two standard deviations away from the mean ($80,000 ± 2*$6,000), the percentage of salaries outside this range (less than $68,000 or more than $92,000) is about 5%.

Professors at a Local University Earn an Average Salary of $80,000