Answer
a) $= 7238.23$ cm$^{3}$
b) $r = 12.41$ cm
Work Step by Step
a)
$V = \frac{4}{3}\pi r^{3}$
$= \frac{4}{3}\pi (12)^{3}$
$ = \frac{4}{3}\pi (1728)$
$= \frac{6912\pi}{3}$
$= 2304\pi$
$= 7238.23$ cm$^{3}$
b)
$8011 = \frac{4}{3}\pi r^{3}$
$8011 = \frac{4\pi r^{3}}{3}$
$24,033 = 4\pi r^{3}$
$6008.25 = \pi r^{3}$
$\frac{6008.25}{\pi} = r^{3}$
$r = (\frac{6008.25}{\pi})^{\frac{1}{3}}$
$r = 12.41$ cm