The problem says that V(x)
varies directly with its length. This is a proportionality problem. So, V(x) =
kl. If you are given a length of 25 inches and a k (proportionality constant)
of 15, you are required to find its volume V(x).
V(x) = kl
V(x) = (15) (25 inches)
V(x) = 375 cubic inches
The volume of the box is 375
cubic inches.
