Justin is wrong because the radius is not squared, the actual radius is r = 3m.
First, remember that for a sphere of radius R the surface is:
[tex]S = 4pi*r^2[/tex]
So you already can see that Justin is wrong, because the radius in his expression is not squared.
Now to be complete, let's find the radius:
[tex]113.04 m^2 = 4*(3.14)*r^2\\\\\sqrt{\frac{113.04 m^2}{4*3.14} } = r = 3m[/tex]
If you want to learn more about spheres:
https://brainly.com/question/10171109
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