Auctio sells sprockets in a perfectly competitive market. Below are its short-run total variable costs at different output levels. The firm's fixed cost is $5. The market price of one sprocket is $8. Units Total Variable Cost 0 $0 1 $12 2 $18 3 $22 4 $28 5 $35 6 $43 What is the average total cost of the 5th unit