Answer
Using technology, the best quadratic model is when $a=0$; that is, when the model is a linear model (a), it is the best fit.
Work Step by Step
Using the desmos project created in part (a), we change the model to $\quad y\sim ax_{1}^{2}+bx+c$ to obtain
$a=0\qquad $(making this a linear model, the same as in part a)
$b=-0.04$
$c=1.46$
