Answer
$f(x) =-1.3(x-3.7)^2+8.7$
Work Step by Step
$$\begin{aligned}
f(x) &= -1.3(x-3.1)^2+18.6
\end{aligned}$$ The best eyeball fit to the data can be found by setting the constants $h= 3.7, k = 8.7 $. Hence, we have $f(x) =-1.3(x-3.7)^2+8.7 $ as the best eyeball fit to the data.
