7. When the height of the sand in a particular rectangular sandbox is
leveled out then the height of the sand, in inches (in.), is proportional to
the volume of sand, in cubic inches (in.3), in the sandbox. When the
height of the sand is 1.25 in. the volume of the sand is 280 in.3. A
playground has 3 of these sandboxes.
What is the total volume of the sand, in cubic inches (in.3), that is
needed for the playground when the height of the sand in each sandbox
is 4.5 in.?
Show your work in the provided space.