Question

Business Weekly conducted a survey of graduates from 30 top MBA programs. On the basis of the survey, assume the mean annual salary for graduates 10 years after graduation is $152,000. Assume the standard deviation is $42,000. Suppose you take a simple random sample of 20 graduates. Round all answers to four decimal places if necessary.

What is the distribution of X ? X ~ N( , )

What is the distribution of ¯¯¯ X ? ¯¯¯ X ~ N( , )

For a single randomly selected graduate, find the probability that her salary is between $152,113 and $162,509.

For a simple random sample of 20 graduates, find the probability that the average salary is between $152,113 and $162,509.

For part d), is the assumption of normal necessary? Yes OR No

Answer 1