1. The total cost of a business is its fixed costs plus its variable costs. For items like the cost ...

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1. The total cost of a business is its fixed costs plus its variable costs. For items like the cost of its buildings, there is no change (in the short term). If two analysts create linear programs using the same constraints, and one has the goal of minimizing total cost while the other has the goal of minimizing variable cost, why would their optimal solutions give the same values of the decision variables? (This is why we ignore fixed costs when solving these programs.) 2. What are the goal, the decision variables, and the constraints (in English and in mathematical equations) of the following problem (do not solve it, just set up the equations): A 24-hour pharmacy/drug store needs to plan for staffing but wants to cut costs to a minimum. The employees work 8-hour shifts. The pharmacy/drug store needs 12 staff between 8 am and noon, 10 staff between noon and 4 pm, 14 staff between 4 pm and 8 pm, 10 staff between 8 pm and 12 am, and only 6 staff between 12 am and 8 am. How should the drug store employees be scheduled? (Assumption: Schedule of staff is only on 4-hour intervals of midnight, 4am, 8am, noon, 4pm, and 8pm.) 3. Like question 2 above, what are the goal, the decision variables, and the constraints (in English and in mathematical equations) of the following problem (do not solve it, just set up the equations): A public relations firm has been contracted to perform a patient satisfaction survey for PA General Hospital. The firm must assign interviewers to conduct the survey by telephone or in person. One public relations firm’s interviewer can conduct 80 telephone interviews or 40 personal interviews in a single day. PA General Hospital has also established following requirements: At least 3,000 interviews must be conducted At least 1,000 interviews must be by telephone At least 800 interviews must be personal An interviewer conducts only one type of interview each day. The cost is $150 per day for a telephone interviewer and $200 per day for a personal interviewer. The PA General Hospital and the public relations firm are in negotiations. Therefore, in bargaining, the PA General Hospital needs to understand the minimum number of interviews to pay the public relations firm in order to minimize cost to the hospital.