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 $163,000. Assume the standard deviation is $33,000. Suppose you take a simple random sample of 7 graduates. Round all answers to four decimal places if necessary. a. What is the distribution of X? X ~ N( b. What is the distribution of ? ~ ~ N( c. For a single randomly selected graduate, find the probability that her salary is between $164,391 and $171,527. d. For a simple random sample of 7 graduates, find the probability that the average salary is between $164,391 and $171,527. e. For part d), is the assumption of normal necessary? O YesO No