n- ? 1) When loan officers speak to people about taking out a loan for a certain principal, P at a certain monthly rate, they always have to balance two quantities, the monthly payment, m] with the number of payments, n] it takes to pay off the loan. These two vary inversely. All of these quantities can be related by the formula: Por 1-(1+r)¯" m= Calculate the monthly payment needed to pay off a $200,000 loan at 4% yearly interest over a 20-year period.. 110