Which statement about a short-run production process is NOT correct?

The statement that is not correct in the context of a short-run production process is the one that suggests if total product is at a maximum, then average product is also at a maximum. When total product reaches its maximum, it implies that production has hit a peak level, leading to diminishing returns as more input is added. At this point, marginal product—defined as the additional output from one more unit of input—can still be positive but declining, and average product, which is total product divided by the number of units of input used, may not necessarily reach its maximum. The average product can continue to decrease as inputs become less effective in generating additional output, even when the total product is at a maximum.

In contrast, the other statements hold true within the short-run production framework. Total costs will continue to rise as production does not cease even when reaching maximum output, as fixed costs remain based on input levels. Marginal product can remain positive up until the point that it reaches zero, just before a decline into negative returns. Therefore, it is essential to understand how these production concepts interact to accurately assess the implications of maximum total output on average and marginal product.