The finance charge is the amount that Emma will pay in order to cover the processing costs of the bedroom set. In this case it would be $520.28. You have first find the down payment cost ($384) and then find how much she needs to pay each month to cover the rest of the cost ($66.34) and multiply it by the 42 months to get $2786.28. Add the down payment onto that and subtract the original cost and you will get your finance charge of $520.28. Hope this helps!
