if its diameter is 12, then its radius is half that or 6.
[tex]\textit{volume of a sphere}\\\\ V=\cfrac{4\pi r^3}{3}~~ \begin{cases} r=radius\\[-0.5em] \hrulefill\\ r=6 \end{cases}\implies V=\cfrac{4\pi (6)^3}{3}\implies V=\cfrac{4}{3}\cdot \pi \cdot 6^3 \\\\\\ V=\cfrac{864}{3}\cdot \pi \implies V=\cfrac{864}{3}\cdot 3.14\implies V\approx 904.32~cm^3[/tex]
