Tommy borrowed $600 at 9% for 12 months under a monthly installment plan. he must pay $8.7453 per $100 each month for 12 months. how much is his monthly installment payment?
You are given the payment per $100, so for $600 your monthly payment is
8.7453(12) = $104.94
The fact that they told us the rate was 9% wasn't even needed.
checking on their information:
let the monthly payment be p
monthly rate = .09/12 = .0075
p(1 - 1.0075^-12)/.0075 = 100
p = 8.745147...
Did you notice that they were slightly off in their information?