## College Algebra 7th Edition

(a) $P=ks^{3}$ (b) $P=0.012s^{3}$ (c) $324$ Watts
(a) Since $P$ is directly proportional to the cube of $s$, we have: $P=ks^{3}$ (b) We are given: $P=96$ and $s=20$, so we have: $96=k* 20^{3}$ $k=0.012$ Therefore: $P=0.012s^{3}$ (c) We are given $s=30$ and need to find $P$: $P=0.012*30^{3}=324$ Watts.