4. A fi rm is considering changing its plant size, so it calculates the average cost of production for various plant sizes below. If the fi rm is currently using plant size C, is the fi rm experiencing economies of scale, diseconomies of scale, or constant returns to scale?

Plant size Average total cost A (smallest) $10,000 B 9,500 C 9,000 D 8,800 E 8,800 F (largest) 8,900

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