Up, Up, and Away is a producer of kites and windsocks. Relevant data on a bottleneck operation in the shop for the upcoming fiscal year are given in the following table: Item Kites Wind Socks Demand forecast 30000 units/ycar 10000 unit/year Lot size 30 units 60 units Standard processing time Standard Setup time 0.3 hour/unit 0.5 hour/unit 3 hour/lot 4 hour/lot The shop works two shifts per day, 8 hours per shift, 200 days per year. Currently, the company operates four machines and desires a 25 percent capacity cushion. How many machines should be purchased to meet the upcoming year's demand without resorting to any short-term capacity solutions?