Question

# A car traveling at a certain speed will travel 76 feet per second. How many miles will the car travel in 3.1 hours if it maintains the same speed? Round to the nearest tenth. (Hint: There are 5,280 feet in one mile)

Ratios, rates, proportions
First, we convert the speed from f/s to mi/hr: $$\displaystyle{\left({76}{f}\frac{{t}}{{s}}\right)}\cdot{\left({1}{m}\frac{{i}}{{5280}}{f}{t}\right)}\cdot{\left({60}\frac{{s}}{{1}}\min\right)}\cdot{\left({60}\frac{\min}{{1}}{h}{r}\right)}\sim{51.82}{m}\frac{{i}}{{h}}{r}$$
So in 3.1 hours, the car will travel: $$\displaystyle{51.82}{m}\frac{{i}}{{h}}\cdot{3.1}{h}\sim{160.6}$$ miles