Question

The formula for the volume of a sphere is V=4/3πr³, where V is the volume and r is the radius. Solve the formula for r, and then use it to answer the question.

The volume of a soccer ball is about 371 cubic inches.

What is the radius of the soccer ball, to the nearest tenth of an inch? Use 3.14 for π. Help.

Answer 1

4.5 inches to the nearest tenth

Explanation:

V=4/3πr^3

Divide both sides by 4/3π:

r^3 = V / 4/3π

r = ∛ (V / 4/3 π)

When V = 371 inches:

r = ∛ (371/ 4/3 π)

= 4.46 in

Answer 2

B. 4.5 in

Explanation:

volume of sphere V = 4/3 π r³

where V = 371 in³

π = 3.14

find: radius r

solution:

371 = 4 (3.14) r³

3

simplify:

371 (3) = 4(3.14) r³

371 (3) = r³

4(3.14)

r³ = 1113

12.56

r =
`\sqrt[3]{88.61}`

r = 4.5 in. therefore, the answer is B.