I need help with these i don’t understand because they seem fine

Combine the information in the problem and the chart using the average balance method to solve the problem.

Interest begins accruing the date of the transaction except for auto loans mortgages credit card cash advances credit card purchases

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?