A construction project is normally distributed with a mean of 60 weeks and a standard deviation of 4 weeks.

( a).What is the probability the project will be finished within 58 weeks?

(b).If the due date of this project is set at 60 weeks, what is the probability that the contractor will have to pay a penalty (i.e., the project will not be completed on schedule)?

( c).What is the probability that the project will be finished in 66 weeks or less?

(d).What is the probability that the project will take longer than 65 weeks?