Nicole's proportion problems

If 3 twinkies cost $1.00, How much is it for 15 twinkies?
Let x be how much 15 twinkies cost
             Model
Twinkies        Cost  
      3                 1
     15                x

             Work

          3x=1*15

             3x  15

              3     3

               x=5

15 twinkies would cost $5.00 

You can buy 2 hot dogs for $3. How much would it be for 4 hotdogs?

Let x be how much 4 hot dogs cost

            Model
 Hot Dogs        Cost  
      2                  3
      4                  x

             Work

            2x=3*4

             2x   12

              2     2

               x=6

4 hots dogs would cost $6.00 

Now solve this one!

Darrell  drove 187 miles in 3 hours, What was Darrell's average rate of speed in miles per hour?