Respuesta :

if the diameter is 7, the radius is half that or 3.5, thus

[tex]\bf \textit{volume of a sphere}\\\\ V=\cfrac{4\pi r^3}{3}~~ \begin{cases} r=radius\\ -----\\ r=3.5 \end{cases}\implies V=\cfrac{4\pi (3.5)^3}{3}\implies V=\cfrac{171.5\pi }{3}[/tex]