4.Don James purchased a new automobile for $20,000. Don made a cash down payment of $5,000 and agreed to pay the remaining balance in 30 monthly installments, beginning one month from the date of purchase. Financing is available at a 24% annual interest rate. Required: Calculate the amount of the required monthly payment. Lang Warehouses borrowed $100,000 from a bank and signed a note requiring 20 annual payments of $13,388 beginning one year from the date of the agreement. Required: Determine the interest rate implicit in this agreement.