The cost C (in dollars) of producing x units of a product is given by C = 0.2x2 + 10x + 5 and the average cost per unit C̅ is given by C̅= C / x = 0.2x2 + 10x + 5 / x, x > 0. Sketch the graph of the average cost function and estimate the number of units that should be produced to minimize the average cost per unit.