a. We want to find the predicted emissions from the quadratic model in 2017.
Here, x = 2017 - 2008 = 9. given that the function is;
[tex]y=0.0429x^2-9.73x+621[/tex]Inserting x = 9, we have;
[tex]\begin{gathered} y=0.0429(9^2)-9.73(9)+621 \\ \end{gathered}[/tex]y = 536.9 million metric tons