McGraw Hill Integrated II, 2012
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McGraw Hill Integrated II, 2012 View details
Practice Test
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Exercise 10 Page 875

Use the formula for the circumference of a circle to find its radius.

About 29.19 cubic inches

A regulation softball can be modeled by the following sphere with a circumference of C=12 inches.

Let r denote its radius. We know that the circumference of the ball is 12 inches. We are asked to find its volume. First, let's find r using the formula for the circumference of a circle.
C=2π r
12=2π r
Solve for r
2π r=12
r=12/2π
r=6/π
r=1.909859...
r≈ 1.91
Therefore, the radius of the sphere is about r=1.91 inches. Now, let's use the formula for the volume of a sphere.
\textcolor{darkorange}{V_\text{ball}}=\dfrac{4}{3}\pi r^3
Substitute 1.91 for r and evaluate
\textcolor{darkorange}{V_\text{ball}}=\dfrac{4}{3}\pi({\color{#0000FF}{1.91}})^2
\textcolor{darkorange}{V_\text{ball}}=\dfrac{4}{3}\cdot 6.967871\pi
\textcolor{darkorange}{V_\text{ball}}=\dfrac{4\cdot 6.967871\pi}{3}
\textcolor{darkorange}{V_\text{ball}}=\dfrac{27.871484\pi}{3}
\textcolor{darkorange}{V_\text{ball}}=29.186949\ldots
\textcolor{darkorange}{V_\text{ball}}\approx \textcolor{darkorange}{29.19}
We find that the volume of the softball is about 29.19 cubic inches.