A manufacturer buys a certain part in varying quantities throughout the year. Ordering cost is $12 per order, and holding cost is $0.15 per unit per month. Month 1 2 Demand (units) -- 86 16 35 4 5 6 7 8 32 32 Given the above demand (net requirements) for the part for the next eight months, determine the order sizes and timing of purchase orders using the part-period method. Buy units and units at the start of month and month ], respectively