The formula for the volume of a sphere is [tex]V=\frac{4}{3} \pi r^3[/tex], where [tex]V[/tex] is the volume and [tex]r[/tex] is the radius. Solve the formula for [tex]r[/tex], and then use it to answer the question.

The volume of a volleyball is about 288 cubic inches.
What is the radius of the volleyball, to the nearest tenth of an inch? Use 3.14 for [tex]\pi[/tex].

A. 4.3 inches
B. 4.1 inches
C. 4.5 inches
D. 4.7 inches



Answer :

To solve for the radius [tex]\( r \)[/tex] of a sphere when given its volume [tex]\( V \)[/tex], we start with the volume formula for a sphere:

[tex]\[ V = \frac{4}{3} \pi r^3 \][/tex]

Given the volume [tex]\( V = 288 \)[/tex] cubic inches, and using [tex]\( \pi \approx 3.14 \)[/tex], we substitute these values into the equation:

[tex]\[ 288 = \frac{4}{3} \times 3.14 \times r^3 \][/tex]

First, simplify the constants on the right-hand side:

[tex]\[ \frac{4}{3} \times 3.14 = 4.1866667 \][/tex]

So the equation simplifies to:

[tex]\[ 288 = 4.1866667 \times r^3 \][/tex]

Next, solve for [tex]\( r^3 \)[/tex] by isolating it:

[tex]\[ r^3 = \frac{288}{4.1866667} \][/tex]

By performing the division:

[tex]\[ r^3 \approx 68.7898 \][/tex]

Now, to find the radius [tex]\( r \)[/tex], take the cube root of both sides of the equation:

[tex]\[ r = \sqrt[3]{68.7898} \][/tex]

Performing the cube root calculation gives:

[tex]\[ r \approx 4.0974 \][/tex]

Finally, round this value to the nearest tenth of an inch:

[tex]\[ r \approx 4.1 \][/tex]

So, the radius of the volleyball, to the nearest tenth of an inch, is:

[tex]\[ \boxed{4.1} \][/tex]

The correct answer is B. 4.1 inches.