The cost, $C$, in dollars, of a taxi ride can be modeled by a linear equation of the form $C=mx+b$, where $x$ is the number of miles traveled. A taxi charges an initial fee of $3.50 and an additional $2.25 for each mile traveled. What is the total cost, in dollars, for a taxi ride that is 10 miles long? (Disregard the $ sign when gridding your answer.)