Mr. Shuaiming Gong bought a house with a market value of $550,000. In order to avoid mortgage insurance, he put 30% down on it. It is a conventional 25 year fixed-rate mortgage with a 4.5% contract rate. Determine the following: (a) his monthly payment, (b) monthly interest payment on month 12, (c) monthly principal payment on month 32. (d) If no prepayments are made, what should be his remaining balance at the end of the 5^th year?