The time to complete a construction project is normally dist

The time to complete a construction project is normally distributed with a mean of 45 weeks and standard deviation of 4.5 weeks.

(a). What is probability the project will be finished in 53 weeks or less?

(b). What is the probability the project will be finished in 40 weeks or less?

(c). What is probability the project will take more than 57 weeks?

mean = 45

s.d = 4.5

a.) P(X<53) = P(Z<(53-45)/4.5) = P(Z<1.78) = 0.9625

b.) P(X<40) = P(Z<(40-45)/4.5) = P(Z<-1.11) = 1 - 0.8665 = 0.1335

c.) P(X>57) = P(Z>(57-45)/4.5) = P(Z>2.67) = 1 - 0.9962 = 0.0038