A family in Melbourne purchased a house in October 2019. A local bank approved a loan of L = $500,000 at a fixed annual interest rate of r = 3.25% for this family to settle the purchase. The loan need to be paid over 25 years through monthly repayments of an equal amount m (in dollars). Note that m depends on r and is treated as a function of r denoted as m(r). (1) Calculate the monthly repayment amount m(r) when r = 3.25%. (2) Use the following first-order approximation to approximate the monthly repayment if the interest rate is reduced by 0.25% (that means the interest rate becomes 3%). m(r) m(ro) + m' (ro) x (raro), wherer = 3% and ro = 3.25%