Answer
$\approx 28.0$ miles/gallon
Work Step by Step
We see that Kim drove 344.1 miles on 12.3 gallons. To find out the number of miles driven per gallon, we divide (using a calculator):
$344.1\div 12.3=^{calculator} 27.975 \approx 28.0$ miles/gallon
(We round to the nearest tenth.)