$3 \text{ miles} \times \frac{1 \text{ foot}}{5,280 \text{ miles}}$

$3 \text{ miles} \times \frac{5,280 \text{ feet}}{1 \text{ mile}}$

$3 \text{ feet} \times \frac{5,280 \text{ miles}}{1 \text{ foot}}$

$3 \times 5,280 \text{ miles}$