The graph shows the costs curves for a blow drier firm. At 50 units, average variable cost (AVC) is $10; marginal cost (MC) is $16; average total cost (ATC) is $26. At 100 units, average variable cost (AVC) is $16; marginal cost (MC) is $24; average total cost (ATC) is $24. At 220 units, marginal cost (MC) is $30; average total cost (ATC) is $25. At 400 units, average variable cost (AVC) is $24; average total cost (ATC) is $26. At 500 units, average total cost (ATC) is $30. For the graph above depicting the cost curves for a competitive firm, at a price of $30, profit would be [blank]