A cruise boat travels 18 miles downstream and back in $4\dfrac{1}{2}$ hours. If the speed of the current is 3 miles per hour, what is the speed of the boat in still water?

1. Let $x$ represent the speed of the boat in still water, and fill in the table.

   	Distance	Rate	Time
   Downstream
   Upstream

2. Write an equation to model the problem:
   $\text{Downstream time + Upstream time = Total trip time}$
   $=$
3. Solve your equation, and answer the question in the problem.
   $x=$: The speed of the boat in still water is mph.