if it has a diameter of 8.5, then its radius is half that, namely 4.25.
[tex]\bf \textit{volume of a cylinder}\\\\ V=\pi r^2 h~~ \begin{cases} r=radius\\ h=height\\[-0.5em] \hrulefill\\ r=4.25\\ h=11.5 \end{cases}\implies V=\pi (4.25)^2(11.5)\implies V\approx 652.57[/tex]