SOLUTION: The average salary for graduates entering the actuarial field is $40,000. If the salaries are normally distributed with a standard deviation of $5000, find the probability that

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Question 1161599: The average salary for
graduates entering the actuarial field is $40,000. If the
salaries are normally distributed with a standard
deviation of $5000, find the probability that
a. An individual graduate will have a salary over
$45,000.
b. A group of nine graduates will have a group average
over $45,000.

Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
z=(x-mean)./sd which is z>1 for the first, and that is 0.1587
z=(x bar-mean)/sigma/sqrt(n) for the second, and that is 5000*3/5000 or z>3 with probability 0.0013.