Simple math problem need help to solve

Jack Sprater wants to buy a new car. He wants to borrow $18,000 for four or five years. Jack’s credit union offers a simple-interest loan at 9.1% for 48 months, resulting in a monthly payment of $448.78. The credit union does not offer five-year auto loans for amounts under $20,000. If jack borrowed $18,000, this payment would strain his budget.

A local bank offered him a five-year loan at 9.34% APR, with a monthly payment of $376.62. This credit would not be a simple-interest loan. Because Jack is not a depositor in the bank, he would also be charged a $25 credit check fee and a $45 application fee. Jack likes the lower payment, but knows that the APR is the true cost of credit, so he decides to confirm the APRs for both loans before making his decision.

1. What is the APR for the credit union?

2. Use the n-ration formula to confirm the APR on the bank loan.

3. What is the add-on interest rate for the bank loan?

4. By how much would Jack lower the APR on the bank loan if he opened an account to avoid the credit check and application fee?