Refer to Example 11.2 (capital rationing problem).
(a) Represent the problem in graphical form and find the optimal solution using the graphical method.
(b) Solve the capital rationing problem using Excel Solver and compare your results with the solution details provided in Workbook 11.2.
(c) Confirm that the objective function increases by the value of the shadow price of the by-product requirement constraint $(0.175)$ by appropriately reformulating the capital rationing problem and solving it.