Final answer:
When the marginal product of labor is greater than the average product of labor, the average product of labor must be decreasing.
Step-by-step explanation:
When the marginal product of labor (additional production) is greater than the average product of labor, the average product of labor must be decreasing.
The law of diminishing marginal productivity states that as a firm employs more labor, eventually the amount of additional output produced declines.
This means that the marginal product of labor will decrease as more workers are hired.
If the marginal product of labor is greater than the average product of labor, it indicates that the average product of labor is decreasing.
This happens when the additional production brought by the last worker is higher than the average production per worker, thus dragging down the average product.