Final answer:
To maximize profit, the coffee mug company should reduce the quantity below 200 or shut down.
Step-by-step explanation:
To determine the profit-maximizing quantity of output, we need to compare the market price to the average variable cost (AVC) and the average total cost (ATC). At an output level of 200, the marginal cost is $10 and equal to ATC. Since the market price of $8 is less than the ATC, the company should reduce the quantity below 200 to minimize losses. In this case, it would be better to shut down because the company would only incur fixed costs.