Answer
174,240 inches
Work Step by Step
2 $\frac{3}{4}$ mile = in.
Use the unit fraction $\frac{5280 feet}{1 mile}$ to change mile to feet and the unit fraction $\frac{12 inches}{1 foot}$ to change feet to inches. Notice how all the units divide out except inches, which is the unit you want in the answer.
11/4 * $\frac{5280 feet}{1 mile}$ * $\frac{12 inches}{1 foot}$ = 174,240 inches