# What is the standard deviation of distribution of X

What is the standard deviation of distribution of X

Subject(s): Mathematics–Mathematics – Other

Business Weekly conducted a survey of graduates from several top MBA programs. On the basis of the survey, assume the mean annual salary for graduates 10 years after graduation is $136,000. Assume the standard deviation is $30,000. Suppose you take a simple random sample of 15 graduates. Round all answers to four decimal places if necessary.

What is the standard deviation of distribution of

X

?

30000

What is the standard deviation of

¯¯¯

X

?

7759.9667

For a single randomly selected graduate, find the probability that her salary is between $138,281 and $144,554.

For a simple random sample of 15 graduates, find the probability that the average salary is between $138,281 and $144,554.

For part d), is the assumption of normal necessary? YesNo