Minh paid $\$3$ for four doughnuts. At that rate, how much would he pay, in dollars, for four dozen doughnuts?
To find the price of four dozen ($4\times12$) doughnuts, we can multiply the price for four doughnuts by 12. We get $3\times12=36$, so he would pay $\boxed{36}$ dollars for four dozen doughnuts.