Answered

The circumference of a cross-section of a sphere is 12.56 in. (Remember [tex]C = \pi d[/tex]). Find the volume of the sphere. Use 3.14 for [tex]\pi[/tex] and round to the nearest tenth.

A. 10.7 in[tex]^{3}[/tex]
B. 33.5 in[tex]^{3}[/tex]
C. 85.3 in[tex]^{3}[/tex]
D. 267.9 in[tex]^{3}[/tex]



Answer :

Let's solve the problem step by step.

### Step 1: Determine the diameter of the sphere
Given: The circumference [tex]\( C = 12.56 \)[/tex] inches
The formula for the circumference of a circle is [tex]\( C = \pi d \)[/tex], where [tex]\( \pi \approx 3.14 \)[/tex] and [tex]\( d \)[/tex] is the diameter.

[tex]\[ d = \frac{C}{\pi} \][/tex]

Substituting the given values:

[tex]\[ d = \frac{12.56}{3.14} = 4.0 \text{ inches} \][/tex]

### Step 2: Determine the radius of the sphere
The radius [tex]\( r \)[/tex] is half of the diameter.

[tex]\[ r = \frac{d}{2} \][/tex]

Substituting the value of the diameter:

[tex]\[ r = \frac{4.0}{2} = 2.0 \text{ inches} \][/tex]

### Step 3: Determine the volume of the sphere
The formula for the volume of a sphere is:

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

Substituting the values of [tex]\( \pi \)[/tex] and [tex]\( r \)[/tex]:

[tex]\[ V = \frac{4}{3} \times 3.14 \times (2.0)^3 \][/tex]

[tex]\[ V = \frac{4}{3} \times 3.14 \times 8 \][/tex]

[tex]\[ V = \frac{4}{3} \times 25.12 \][/tex]

[tex]\[ V = 33.49333333333333 \text{ cubic inches} \][/tex]

### Step 4: Round the volume to the nearest tenth
To round to the nearest tenth, we look at the first digit after the decimal point which is 4:

[tex]\[ V \approx 33.5 \text{ cubic inches} \][/tex]

### Conclusion
The volume of the sphere, rounded to the nearest tenth, is:

[tex]\[ \boxed{33.5 \text{ cubic inches}} \][/tex]

Therefore, the correct answer is:
[tex]\[ b. 33.5 \text{ in}^3 \][/tex]