A purely competitive wheat farmer can sell any amount of wheat he grows for $20 per bushel. He is using a fixed amount of capital (tractors and plows) and he and his sister are the only workers. Thus cultivating each additional acre of land exhibits diminishing marginal productivity. That is, the first acre can produce 1000 bushels of wheat, the second acre produces 900 bushels, the third acre: 800 bushels and so on. Given this information, complete the table below.