How much concrete is needed for the footing shown in the example?

To determine how much concrete is required for the footing, it's essential to calculate the volume based on the dimensions of the footing provided in the example. The volume of concrete can be found using the formula for the volume of a rectangular prism, which is length × width × height.

If the dimensions of the footing lead to a volume of 16.6 cubic yards, that would be the total amount of concrete needed. This value represents the volume that must be filled to create a structural footing capable of supporting the intended loads.

For the other choices, the volumes mentioned (0.3 cy, 4.2 cy, and 8.3 cy) indicate lesser amounts of concrete that would not match the necessary dimensions or structural requirements for the footing based on the specific example presented. Therefore, these calculations do not satisfy the conditions set by the dimensions used in the question scenario.