4. Suppose you want to buy a new house priced at $400,000. After paying 20% down payment ($80,000), you want to use a 15-year mortgage loan to pay the rest of the house price ($320,000). If the bank that offers you the mortgage loan tells you that your monthly mortgage payment will be $2,367. What is the APR the bank is charging you? (Annual Percentage Rate (APR) is an annualized rate for the convenience of quotation. APR= period rate number of periods per year).