After visiting several automobile dealerships, Richard selects the car he wants. He likes its $$10,000$ price, but financing through the dealer is no bargain. He has $$2,000$ cash for a down payment, so he needs a loan of $$8,000.$ In shopping at several banks for an installment loan, he learns that interest on most automobile loans is quoted at add$-$on rates. That is$,$ during the life of the loan, interest is paid on the full amount borrowed even though a portion of the principal has been paid back. Richard borrows $$8,000$ for a period of four years at an add$-$on interest rate of $11$ percent.

a$.$ What is the total interest on Richard's loan?

b$.$ What is the total cost of the car?

c$.$ What is the monthly payment?

Monthly paymenT?

d$.$ What is the annual percentage rate?