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3. Demand for walnut fudge ice cream at the Sweet Cream Dairy can be approximated by a normal distribution with a mean of 35 gallons per week and a standard deviation of 9.5 gallons per week. The new manager desires a service level of 90 percent. Lead time is two days, and the dairy is open seven days a week. (Hint: Work in terms of weeks.) If a fixed-interval model is used, what order size would be needed for the 90 percent service level with an order interval of 10 days and a supply of 50 gallons on hand at the order time? Extra Credit The chart below depicts 16 sample means that were taken at periodic intervals and plotted on a control chart. Does the output appear to be random? Please use run tests to check. 45 40 35 30 UCL MEDIAN -LCL SAMPLE 25 20 15 10 12 10 13 14 15 16 s 1 2 3