The average rate of change can be found through the formula
[tex]average=\frac{f(b)-f(a)}{b-a}[/tex]
then, looking at the graph, the points that are needed are (14,750) and (9,1400).
Using the formula,
[tex]\begin{gathered} average=\frac{1400-750}{9-14} \\ average=\frac{650}{-5} \\ average=-\text{\$}\frac{130}{\text{year}} \end{gathered}[/tex]
