The slope coefficient estimate b from a regression of profits on sales of a number of
firms in the coal industry is 0.075. How should you interpret this coefficient?
a. Average profit in the coal industry is 7.5%.
b. If a firm in the coal industry were to increase its sales by $1, its profits would rise on
average by $0.075.
c. If a firm has 1 more dollar in sales than another firm in the coal industry, it will have
7.5 more cents in profit on average.
d. Average profit in the coal industry is .75%.
e. If a firm in the coal industry were to increase its sales by $1, its profits would rise on
average by $0.0075.
If the monopolist shown in the following figure could practice first-degree price
discrimination, the consumer surplus would be:
a. $0.
b. $225.
c. $450.
d. $900.