Brooke is a beautician who is opening her own salon. She needs $$8,500$ to purchase furniture and equipment. Brooke makes a $10\%$ down payment and finances the balance on a $48-$month loan with an interest rate of $4\%$ per year compounded monthly. What is Brooke's monthly payment?

Part $1$ of $2$

Which formula should be used to find Brooke's monthly payment?