Question 736840
The surface area of a sphere = {{{4*pi*r^2}}}<P>
{{{324*pi = 4*pi*r^2}}}<P>
{{{324 = 4*r^2}}}<P>
{{{81 = r*2}}}<P>
9=r.<P>
The diameter is twice the radius = 2*9 = 18 inches.
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