I need help with these questions. Please indicate your full solution and correct answers. Thank you

Chad purchased a house for $325,000. He made a down payment of 20.00% of the value of the house and received a mortgage for the rest of the amount at 3.12% compounded semi-annually amortized over 15 years. The interest rate was fixed for a 6 year period. a. Calculate the monthly payment amount. Round to the nearest cent b. Calculate the principal balance at the end of the 6 year term. Round to the nearest cent c. Calculate the monthly payment amount if the mortgage was renewed for another 6 years at 3.72% compounded semi-annually? Round to the nearest cent