Patrick received a mortgage for a property he was interested in investing in for a while. The mortgage lasts thirty years with a3.5% annual interest rate for a total of $300,000. These conditions result in a yearly payment (debt service) of $16,311.40. What will be the interest and principal payments for the first four years of the mortgage? What will be the remaining principal balance at the end of the8thand12thyear? (Show your calculations.)