$$\frac{x \ miles}{2\frac{3}{4}inches}=\frac{16\ miles}{\frac{1}{4}\ inches}\\$$ $$\Rightarrow \frac{x}{\frac{11}{4}}=\frac{16}{\frac{1}{4}}\\$$ $$\Rightarrow \frac{x}{11}=\frac{16}{1}\\$$ $$\Rightarrow x=16\times11=176 \ miles$$