Allied company machines produces the output that it sells in the highly competitive market at the price of $100 per unit. Its inputs include two machines (which cost the firm $50 each) and workers, who can be hired on an as-needed basis in a labor market at a cost of $2,800 per worker. Based on the following production data, how many workers should the firm employ to maximize its profits.

Machines Workers Output
2 0 0
2 1 60
2 2 100
2 3 129
2 4 148
2 5 160
2 6 168