The following table shows the demand for a product produced by a monopolist, who has a constant marginal cost and an average total cost of $45 per unit.

Quantity (thousands of units)	Price (dollars per unit)
0	120
1	105
2	90
3	75
4	60
5	45
6	30

a. Calculate the total revenue and marginal revenue for level of quantity.

b. What are the profit-maximizing level of output and the price of the product?In no more three sentences, explain why.

c. Calculate the monopolist's profit.

d. Calculate the Lerner Index for this industry.