Answer
$$87.21\space mi/h$$
Work Step by Step
Divide by $4.3$ to make the denominator $1$ unit
$$\frac{375\space mi}{4.3\space h} = \frac{375\space mi\div 4.3}{4.3\space h\div 4.3}\approx\frac{87.21\space mi}{1\space h} \approx 87.2\space mi/h$$