Mitchell has outgrown the bike he rode when he was small. So, for his twelfth birthday, his parents surprise him with a five-speed Blaze Rider 2000! Mitchell has never had a bike with multiple speeds before, and he is eager to learn how it works. He starts by testing the middle speed. The wheels rotate 2 times for every time Mitchell pedals.
There is a proportional relationship between the number of times Mitchell pedals, x, and the number of times the wheels rotate, y.