Jordan has started a new dog-walking service. His total profits over the first 4 weeks are expressed in this table. Time(weeks) Profits($)

1 150

2 300

3 450

4 600

Show that his business results can be described by a linear function. Graph this function and use the graph to predict his business profit 9 weeks after he opens. Explain why it is or is not a good idea to project his profits so far into the future. Give examples to support your answer.