Given the information on the proble, we can use the formula for simple interest to find the principal amount to be invested:
![\begin{gathered} A=P(1+rt) \\ \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/rwr84ho042d7q4diprtd3k9ftyo7qzxu1u.png)
where P represents the principal amount, r the interest rate, t represents the time and A is the total amount.
In this case we know that A = 12000, since that is the price of the car in four years. With r = 7.3% = 0.073 and t = 4, we have:
![\begin{gathered} 12000=P(1+0.073*4)=1.292P \\ \Rightarrow P=(12000)/(1.292)=9287.93 \\ P=9287.93 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/g73n153lj86bksoz5xno7f5zrxkrhkel5g.png)
therefore, the amount to be invested is $9287.93