Question

We can use the formula r=radical S/12.6 to relate a ball's surface area S (in square inches) to its radius r (in inches). Suppose a ball has a surface area of 176.4 square inches. What is its radius?Round your answer to the nearest tenth.

Answer 1

Using the given formula with the value of S = 176.4 in², let's calculate the value of r:

`\begin{gathered} S=4\pi r^2\to r=\sqrt[]{(S)/(4\pi)}=\sqrt[]{(S)/(12.6)} \\ \\ r=\sqrt[]{(176.4)/(12.6)} \\ r=\sqrt[]{14} \\ r=3.7 \end{gathered}`

So the ball radius is 3.7 inches.