Consider the following table of long-run total cost for three different firms:
Quantity 1 2 3 4 5 6 7
Firm A $60 $70 $80 $90 $100 $110 $120
Firm B 11 24 39 56 75 96 119
Firm C 21 34 49 66 85 106 129
a. Calculate long-run average cost for each firm for each output level.
b. Does each of these firms experience economies of scale or diseconomies of scale?