a. We want to convert 3 1/4 (or 3.25) miles into feet. We can use the next proportion:
[tex]\frac{5280\text{ feet}}{x\text{ feet}}=\frac{1\text{ mile}}{3.25\text{ miles}}[/tex]Solving for x, we get:
x = 5280*3.25/1
x = 17160 feet
b. We want to convert 17160 feet into inches. We can use the next proportion:
[tex]\frac{12\text{ inches}}{x\text{ inches}}=\frac{1\text{ foot}}{17160\text{ feet}}[/tex]Solving for x, we get:
x = 12*17160/1
x = 205920 inches