The annual salary for a a group of highly educated professionals is normally distributed with a mean = $157,000. Is also known that 62% earn more than $125,000.
A. What is the standard deviation?
B. what percent earn less than $165,000?
C. What percent earn between $120,000 and $145,000?
D. Determine the annual salary X1 for which 13% earn more than X2.
E. A random sample of 15 professionals is chosen from the group. What is the probability that at most 2 make more than $170,000?
F. A random sample of 25 professionals is chosen from the group. What is the probability that the mean salary of the sample of more than $160,000?