This is for RStudio The incomes in a certain large populatio

This is for RStudio:

The incomes in a certain large population of college teachers have a distribution with a mean of

Solution

(a) Normal distribution with mean=35000 and standard deviation =s/vn= 5000/sqrt(400) =250

-------------------------------------------------------------------------------------------------------------------------

(b) So the probability that the average salary of the 400 teachers will exceed $35,615 is

P(xbar>35615 ) = P((xbar-mean)/(s/vn) >(35615-35000)/250)

=P(Z>2.46) =0.0069 (from standard normal table)