a Natalie purchased a house for $500,000. He made a down payment of 15.00% of the value of the house and received a mortgage for the rest of the amount at 4.12% compounded semi-annually amortized over 15 years. The interest rate was fixed for a 4 year period. a. Calculate the monthly payment amount. Round to the nearest cent b. Calculate the principal balance at the end of the 4 year term. Round to the nearest cent c. Calculate the monthly payment amount if the mortgage was renewed for another 4 years at 3.12% compounded semi-annually