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][tex]$r$[/tex][/tex] is the radius. Solve the formula for [tex]$r$[/tex], and then use it to answer the question.

The volume of a basketball is about 435 cubic inches.

What is the radius of the basketball, 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 given its volume [tex]\( V \)[/tex], we start with the formula for the volume of a sphere:

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

Given that the volume [tex]\( V \)[/tex] is 435 cubic inches, and using [tex]\( \pi = 3.14 \)[/tex], we can substitute these values into the equation:

[tex]\[ 435 = \frac{4}{3} \times 3.14 \times r^3 \][/tex]

First, we isolate [tex]\( r^3 \)[/tex]. To do this, we will multiply both sides of the equation by the reciprocal of [tex]\( \frac{4}{3} \times 3.14 \)[/tex]:

[tex]\[ r^3 = \frac{435 \times 3}{4 \times 3.14} \][/tex]

Now let's calculate the value inside the fraction:

[tex]\[ r^3 = \frac{1305}{12.56} \][/tex]

By performing the division, we get:

[tex]\[ r^3 \approx 103.90 \][/tex]

Now, to solve for [tex]\( r \)[/tex], we need to take the cube root of 103.90:

[tex]\[ r \approx 103.90^{\frac{1}{3}} \][/tex]

Using a calculator or approximating the cube root, we find:

[tex]\[ r \approx 4.70 \][/tex]

To the nearest tenth of an inch, the radius [tex]\( r \)[/tex] of the basketball is:

[tex]\[ r \approx 4.7 \text{ inches} \][/tex]

Therefore, the correct answer is:

D. 4.7 inches