Francis has a credit card that uses the previous balance method. The opening balance of one of his 30-day billing cycles was $0, but this was his balance
for only the first 15 days of the billing cycle. He then made a purchase that
increased his balance to $3600, and his balance stayed this amount for the
remainder of the billing cycle. If his credit card's APR is 21%, how much was
Francis charged in interest for the billing cycle?

Using pert, adam munson was able to determine that the expected project completion time for the construction of a pleasure yacht is 21 months, and the project variance is 4. a) what is the probability that the project will be completed in 17 months? b) what is the probability that the project will be completed in 20 months? c) what is the probability that the project will be completed in 23 months? d) what is the probability that the project will be completed in 25 months? e) what is the due date that yields a 95% chance of completion?