For 10 points, name this quantity that represents the cost of borrowing money.
Factors of 1 plus this value all to the nth power appear in both the numerator and denominator of the amortization formula. Dividing a final value by the nth power of one plus this quantity yields present value. Factors of one plus this quantity to the nth power and one plus n times this quantity, when multiplied by a (*) principal value, represent its compound and simple types. For 10 points, name this quantity that represents the cost of borrowing money.
Factors of 1 plus this value all to the nth power appear in both the numerator and denominator of the amortization formula.
interest rate [accept simple interest rate or compound interest rate]