A car dealer will sell you a used car for $8,544 with $544 down and payments of $272.22 per month for 36 months. What is the simple interest rate? (Round each answer to the nearest tenth.)

(272.22 * 36) - 8,000 = 1799.92

I = PRT

1799.92 = 8,000 * R * 3

1799.92 = 24,000R

1799.92 / 24,000 = R

0.074996 = R

7.5% = R