The amount of time the university professors devote to their jobs per week is normally distributed with a

mean of 52 hours and a standard deviation of 6 hours.

a. What is the probability that a professor works for

more than 60 hours per week?

b. Find the probability that the mean amount of

work per week for three randomly selected professors is more than 60 hours.

c. Find the probability that if three professors are

randomly selected all three work for more than

60 hours per week