Question 62326
While you have the correct formula for the volume of a sphere: {{{V = (4/3)(pi)r^3}}} your interpretation is a little off.  Notice that only the radius, r, is cubed, not the {{{(pi)}}} nor the {{{4/3}}}.

{{{V = (4/3)(pi)r^3}}} Substitute r = 3 and {{{(pi) = 3.14}}} Approx.
{{{V = (4/3)(3.14)(3^3)}}}
{{{V = (4/3)(3.14)(27)}}}
{{{V = (3.14)(36)}}}
{{{V = 113.04}}}Cubic miles.