By comparing the market value of livestock, corn, wheat and oats in 1880 to 1900, one can see that agricultural growth in the South did not occur

Suppose a single-price monopoly sells 3 units of a good at $20 per unit. If the monopoly sells 4 units, the total revenue increases to $72. What is the marginal revenue of the fourth unit?

A) $52 B) $18 C) $60 D) $12 E) $20

If the regulator require a natural monopoly set its price equal to its marginal cost, that would ensure

A) an economic profit for the firm. B) zero economic profit for the firm. C) an economic loss for the firm. D) an accounting loss for the firms.