If you are planning to buy a house for $$250,000$ and you are required to make a down payment of $20\%$ of this value of the house. First calculate how much money you will need to finance this house. If you borrow this amount from a bank who would charge $6\mathrm{.}8\%$ per year for a period of $15$ years, calculate how much money you have to pay every month to repay the equal instalment loan. Also, create an amortization schedule showing the beginning balance, monthly payments, interest paid, principal paid and ending balance on a monthly basis for $15$ years. Calculate the interest payment from month $60$ to $80$ months. Calculate the principal repayment for the months $70$ to $90.$