2. In PC Tech's product mix problem, assume there is another PC model, the VXP, that the company can produce in addition to Basics and XPs. Each VXP requires eight

hours for assembling, three hours for testing, $275 for component parts, and sells for $560. At most 50 VXPs can be sold. a. Modify the spreadsheet model to include this new product, and use Solver to find the optimal product mix. 4. Again continuing Problem 2, suppose that you want to force the optimal solution to be integers. Do this in Solver by adding a new constraint. Select the deci- sion variable cells for the left side of the constraint, and in the middle dropdown list, select the "int" op- tion. How does the optimal integer solution compare to the optimal noninteger solution in Problem 2? Are the decision variable cell values rounded versions of those in Problem 2? Is the objective value more or less than in Problem 2? 26. A furniture company manufactures desks and chairs. Each desk uses four units of wood, and each chair uses three units of wood. A desk contributes $250 to profit, and a chair contributes $145. Marketing restrictions require that the number of chairs produced be at least four times the number of desks produced. There are 2000 units of wood available. a. Use Solver to maximize the company's profit. 46. During each four-hour period, the Smalltown police force requires the following number of on-duty police officers: four from midnight to 4 A.M.; four from 4 A.M. to 8 A.M.; seven from 8 A.M. to noon; seven from noon to 4 P.M.; eight from 4 P.M. to 8 P.M.; and ten from 8 P.M. to midnight. Each police officer works two consecutive four-hour shifts. a. Determine how to minimize the number of police of- ficers needed to meet Smalltown's dailyrequirements. 66. United Steel manufactures two types of steel at three different steel mills. During a given month, each steel mill has 240 hours of blast furnace time available. Because of differences in the furnaces at each mill, the time and cost to produce a ton of steel differ for each mill, as listed in the file P04_66.xlsx. Each month, the company must manufacture at least 700 tons of steel 1 and 600 tons of steel 2. Determine how United Steel can minimize the cost of manufacturing the desired steel.