# Radius of sphere given its volume?

A sphere has a volume of 843 in. What is this spheres radius?

Please show working out too.

### 5 Answers

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- GeorgeLv 710 years agoFavorite Answer
Answer --> 5.86 is the radius

Here is why:

Formula:

Volume = 4/3 * π * r^3

Radius = cubic root(V / π / 4/3)

π = 3.1415926

4/3 = 1.333333

Solving:

Radius^3 = 843 / π / 4/3

Radius^3 = 201.25

Cubic root(201.25) = 5.86

Just check that is right:

Volume = 4/3 * π * r^3

Volume = 4/3 * π * 5.86

Volume = 843

- 4 years ago
Supposed V(sphere) =4/3 pi r^3 = 100 4/3 pi r^3 = 100 with pi = 3 (4/3) x 3 r^3 = 100 4r^3 = 100 r^3 = 100/4(used cube root both sides) r = cube root(100/4) (answer)

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- donpatLv 710 years ago
You have :

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V = [ 4/3 ] [ pi ] [ r ]^3

r = [ ( 3 ) ( V ) / ( 4 ) ( pi ) ]^1/3

r = [ ( 3 ) ( 843 ) / ( pi ) ( 4 ) ]^1/3 = 5.860 in. <--------------------------------

Source(s): I rearranged equation for volume of a sphere.

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