Answer
See below
Work Step by Step
The function is in the form $a(x-p)(x-q)=y$. We know that the axis of symmetry is $\frac{p+q}{2}$.
The first function is $y=- 0.652(x - 5.35)(x-21.8)$
where $a=-0.652\\p=5.35\\q=21.8$
The x-coordinate of the vertex is: $x=\frac{p+q}{2}=\frac{5.35+21.8}{2}=13.575$
Find the y-coordinate: $y=-0.652(13.575-5.35)(13.575-21.8)=44.1082$
Thus, the vertex is $(13.575,44.1082)$
The maximum value of the function is the y-coordinate of the vertex, $y=44.1082$
It occurs when $x=13.575$
Hence, the maximum volume is $44.1082 cm^3/g$, which occurs when the moisture content is $13.575 \%$
