It takes Julian 1/2 hour to walk 2 miles. He decides to start working in his spare time, but because he wants to make sure he has enough time to go a desired distance he created the data table. At which ratio does the constant of proportionality appear?

Hours Miles Walked
1/4. 1
1/2. 2
3/4. 3
1. 4

The ratio of the number of hours to the number of miles walked is always 1:2. Therefore, the constant of proportionality is 1/2.