Answer:
3 (or 3.0)
Step-by-step explanation:
The formula for the volume of a cylinder is [tex]v=\pi r^2h[/tex] where [tex]v[/tex] is the volume, [tex]r[/tex] is the radius, and [tex]h[/tex] is the height. We know the height is 7 inches and the volume of 63pi cubic inches, so plugging in gives:
[tex]63\pi=\pi r^2\cdot 7[/tex].
Dividing by [tex]7\pi[/tex] on both sides gives
[tex]r^2=9[/tex],
and simplifying and taking the positive root leaves [tex]r=3[/tex].