A mortgage company offers a loan for 30 years at an annual rate that is equal to the prime rate published by the Federal Reserve plus 2%. This can be modeled using the function APR(p) = p + 0.02, where p is the prime interest rate as a decimal. The annual interest rate is then converted to a monthly interest rate using the function . The Wilsons want to borrow $128,000. Their monthly payments can be calculated by the function .