Mortgage Analysis Part I You are planning to purchase a house that costs $480,000. You plan to put 20% down and borrow the remainder. Based on your credit score, you believe that you will pay 3.99% on a 30-year mortgage. 1. Use function "PMT" to calculate your mortgage payment. 2. Calculate the total cost of the home purchase. (Down payment plus principle (loan amount) plus interest.) 3. Calculate how much interest you will pay in total? 4. Assume that you plan to pay an extra $300 per month on top of your mortgage payment, calculate how long it will take you to pay off the loan given the higher payment (Use interest rate of 3.99%). Calculate how much interest you will pay in total? Compare this to the value that you calculated for #3