Rational functions abound in real life, we just don't always think of them that way.
For example, suppose you are buying movie tickets for you and your friends:
The theater has a deal going, if you buy one ticket for $12.50, then additional tickets are only $10 each. As you buy more and more tickets (more and more lucky friends!), what is the average cost per ticket? (and more and more and more and...)

How would this value be represented be represented on a graph?