We are given dimensions of the sand box:
Length = 3m.
Width = 2m and
Height = 1 m.
Volume of the box is = Length × Width × Height.
Plugging values in above formula, we get
Volume = 3 × 2 × 1 = 6 cubic meter.
We are given cost $4.50 per cubic meter.
Therefore, total cost is 6 × 4.5 = $27.