The new sailboat you want to buy costs $156,000. After a 25% down payment, amortize a loan with equal monthly payments over a 20-year period. If you pay 6.9% interest on the loan, what is your monthly payment? A family purchased a house 10 years ago for $189, 900. After they put a 20% down payment towards the purchase price they mortgaged the remaining amount for 30 years at 6.5% interest. a) Determine the monthly payment they made each month. b) Determine how much interest the family will pay over 30 years for this mortgage loan