A graph showing short-run average total cost (or ATC), average variable cost (or AVC), marginal cost (or MC), price (or P = D), and marginal revenue (or MR), measuring units of output (or Q) on the horizontal axis ranging from the origin to 300 units, and cost in dollars on the vertical axis ranging from the origin to $14. Average total cost decreases until its minimum at about Q=130, after which it increases. Average variable cost decreases until its minimum at Q=30, after which it increases. M