The revenue R (in millions of dollars) for a company from 1999 to 2005 can be modeled by the equation below, where t is the year, with t = 9 corresponding to 1999. 0.59221t4 - 18.0042t + 175.293t 316.42t - 116.5 R = Revenue (in millions of dollars) Polo Ralph Lauren Revenue R 4000 3500 3000 2500 2000 1500 9 10 11 12 13 14 15 Year (9 1999) t (a) Find the slope of the graph for the year 2000. (Round your answer to two decimal places.) Find the slope of the graph for the year 2003. (Round your answer to two decimal places.) (b) What are the units for the slope of the graph? no units dollars per year dollars millions of dollars per year millions of dollars Interpret the slope of the graph in the context of the problem. The slope of the graph at time t is the effect time has had on sales. The slope of the graph at time t is the total amount of sales. The slope of the graph at time t is the rate at which average sales are increasing. The slope of the graph at time t is the amount by which sales are increasing. The slope of the graph at time t is the rate at which sales are increasing.