Final answer:
To determine the best option for purchasing the high-end audio system, one must calculate the APR for both Dealer A and Dealer B, taking into account the total payments and the number of monthly payments for each.
Step-by-step explanation:
Lina Martinez is considering two options for purchasing a high-end audio system with differing finance terms. To calculate the Annual Percentage Rate (APR) for Dealer A and Dealer B, we need to use the formula for the APR of a loan which accounts for interest as well as the time frame of payments. Calculating the APR for Dealer A requires knowing the total amount paid to the dealer, the loan amount (the price of the system), and the number of monthly payments. In this case, the total payments would be 18 months times $118.28 per month. To find the APR, we would use a financial calculator or an equivalent online tool that allows for the input of these values to solve for the interest rate.
Similarly, for Dealer B, we would calculate the total amount paid over the 36 months at $70.31 per month and again use a financial calculator or online APR calculator to determine the APR.
When deciding between the two, Lina should consider not only the monthly payment amounts but also the total amount paid over time and the APR, as a lower monthly payment might end up costing more in the long run if the APR is higher.