Alex has successfully celebrated their first-year anniversary of opening their cupcake shop. They are using the High-low method to predict next year's future costs. Their records show that they were busiest in May for graduation season and slowest in September when no major events happened. In May he sold 1,200 cupcakes at a cost of $2,087 and in September he sold 550 cupcakes with a cost of $1,456. Find one plausible equation of a line for predictive purposes?