Caitlin received a 30 year loan of $245,000 to purchase a house. The interest rate on the loan was 4.30% compounded semi-annually.

a. What is the size of the monthly loan payment? Round to the nearest cent

b. What is the balance of the loan at the end of year 4? Round to the nearest cent

c. By how much will the amortization period shorten if Caitlin makes an extra payment of $30,000 at the end of year 4?