The Weighty Trash Bag Company has the following price schedule for its large trash can liners. For orders of less than 500 bags, the company charges 30 cents per bag; for orders of 500 or more but fewer than 1,000 bags, it charges 29 cents per bag; and for orders of 1,000 or more, it charges 28 cents per bag. In this case the breakpoints occur at 500 and 1,000. The discount schedule is all-units because the discount is applied to all of the units in an order. The order cost function C(Q) is defined as b (0.30Q for C(Q) = 0.29Q for 0 Q < 500, 500 Q < 1,000, 0.28Q for 1,000 Q Hors 282 will gai The function C(Q) is pictured in Figure 4-9. In Figure 4-10, we consider the same break- points, but assume an incremental quantity discount schedule. Assume that the company considering what standing order to place with weighty uses trash bags at a fairly constant rate of 600 per year. The accounting department estimates that the fixed cost of placing an order is $8, and the holding costs are based on a 20 percent annual interest rate. (a) What is the optimal quantity and cost if all-units discount model is used? (b) What is the optimal quantity and cost if incremental discount model is used?