If inflation has been running at $4.02 \%$ per year and a new car costs $\$ 15,300$ today, what would it have cost 3 years ago?

A car that costs $\$ 15,300$ today would have cost $\$ \square 3$ years ago.
(Do not round until the final answer. Then round to the nearest cent as needed.)

Step 1 ：The problem is asking for the cost of a car 3 years ago given its current cost and the annual inflation rate. To find this, we need to reverse the inflation process.

Step 2 ：Inflation is typically calculated using the formula: \(\text{Final Amount} = \text{Initial Amount} \times (1 + \text{Inflation Rate})^{\text{Number of Years}}\)

Step 3 ：In this case, we know the Final Amount (the current cost of the car), the Inflation Rate, and the Number of Years. We need to solve for the Initial Amount (the cost of the car 3 years ago).

Step 4 ：We can rearrange the formula to solve for the Initial Amount: \(\text{Initial Amount} = \text{Final Amount} / ((1 + \text{Inflation Rate})^{\text{Number of Years}})\)

Step 5 ：Plugging in the given values into this formula, we get: \(\text{Initial Amount} = 15300 / ((1 + 0.0402)^3)\)

Step 6 ：Calculating the above expression, we find that the Initial Amount (the cost of the car 3 years ago) is approximately $13,593.80.

Step 7 ：Final Answer: A car that costs $15,300 today would have cost \(\boxed{\$13,593.80}\) 3 years ago.