Drivers Club of Arizona sponsors educational events that provide high-performance driving instruction on actual race tracks. Because safety is a primary consideration at such events, many drivers choose to install roll bars in their cars. Bigelow Industries manufactures two types of roll bars for race cars: ModelX1isboltedtothecarusingexistingholesinthecar'sframe.Eachroll bar requires 20 pounds of a special high alloy steel, 70 manufacturing time, and 60 minutes of assembly time. Model X2 is a heavier roll bar that must be welded to the car's frame. It requires 25 pounds of the special high alloy steel, 150 minutes of manufacturing time, and 40 minutes of assembly time. Bigelow's steel supplier indicated that at most 20,000 pounds of the high-alloy steel will be available next quarter. In addition, they estimate that 1,750 hours of manufacturing time and 800 hours of assembly time will be available next quarter. The profit per unit amounts are $200 for model X1 and $400 per unit for model X2. 2a) Formulate this problem as a linear programming model, starting with the definition of decision variables, and followed by the objective function and the constraints. 2b) Find the optimal solution using the graphical method (on a graph paper). 2c) Identify