Travis Smith and his brother, Roy, are co-owners of a trucking company. One of their regular weekly jobs is to transport fruit grown in Pecos, Texas, to a Dallas, Texas, distributing plant. Travis knows that his customers are concerned about the speed with which the brothers can deliver the produce, because fruit will spoil after a certain length of time. Answer the following questions based on the graph below.

Determine the slope of the graph. Interpret it in context.