Final answer:
To find the profit-maximizing quantity for AAA Aquarium Co., calculate and analyze the total revenue, total cost, and marginal cost, then graph these to identify where marginal cost equals marginal revenue.
Step-by-step explanation:
The AAA Aquarium Co.'s challenge is to determine the profit-maximizing quantity of aquariums to produce and sell. As with most firms in a perfectly competitive market, they must consider both marginal costs and marginal revenue. To identify this quantity, we must calculate the total revenue, total cost, and marginal cost at each output level. After creating a table with this data, we then sketch the total revenue and total cost curves on one diagram, and the marginal revenue and marginal cost curves on another diagram. The point where marginal cost and marginal revenue intersect will give us the profit-maximizing output level. It's at this point that the additional cost of producing one more unit equals the additional revenue gained from selling that unit.