Answer
See explanation
Work Step by Step
The surface area of a sphere of radius r is given by $4\pi r^2$.
$I=\frac{S}{4\pi r^2}$.
If we set $k=\frac{S}{4\pi}$, we can rewrite the above expression as $I=\frac{k}{r^2}$. The initial energy is a positive value, so $k$ is a positive constant. Thus, $I$ satisfies the inverse square law.
