Nikki borrowed $500 at 9% interest for 12 months under a monthly

installment plan. She must pay $8.7453 per $100 each month for 12
months. How much is her monthly installment payment?

1 answer

Multiply $8.7453 by 5. They already told you the rate per $100 borrowed.

You do not have to use the interest rate in an amortization formula.