David and Barbara took out a $520,000 20-year mortgage 9 years ago at 9.24% compounded monthly Their monthly payment is $4,759.14. Now mortgage rates have fallen to 8.64% compounded monthly, but it will cost $3,000 in closing costs to obtain the new loan. Click here for reference to formulas. (a) What is the payoff amount of their current loan? $ Number (b) If David and Barbara decide to refinance with a new 11-year loan at 8.64%, adding the closing costs into the principal of the new loan, what would be their new monthly payment? $ Number (c) If they expect to make the 11 remaining years of payments, should they refinance? o Yes No