All else constant, an improvement in technology would cause a firm's total, average and marginal product functions to increase (graphically, shift up)

A Herfindahl-Hirschman Index is calculated by

A) summing the amount of sales by the four largest firms and dividing by total industry sales. B) summing the squares of the market shares of each firm in the industry. C) dividing the number of firms wanting to merge by the total number in the industry. D) dividing the advertising expenditures of the firms that want to merge by total industry advertising expenditures.

Five hundred units of good x are currently bought and sold. The marginal buyer is willing to pay $40 for the 500th unit, and the cost to the marginal seller is $35 for the 500th unit. We know that

a. the equilibrium price of good x is somewhere between $35 and $40. b. the equilibrium quantity of good x exceeds 500 units. c. 500 units is not an efficient quantity of good x. d. All of the above are correct.