Answer:
Explain why average total costs decline as output increases in the long run.
Step-by-step explanation:
Economies of scale exist when the long run average total cost of producing a good or service decreases as output increases.
E.g. when a company produces 100 units of good X, its average total cost is $10 per unit. But as the output increases to 500 units of good X, the average total cost decreases to $7 per unit. If the output keeps increasing to 5,000 units, the average total cost will be $3. As output increases, the average total cost decreases.