You just won a $100,000 lottery and plan to invest it among the following alternatives ...

               You just won a   $100,000 lottery and plan to invest it among the following alternatives:   You want to invest this $100,000 in such   a way to maximize your return from investment (in terms of dollars) one year   from now, while meeting the following guidelines:   • You must invest at least $20,000 in GF (9% return),   and at most $30,000 in EF (7% return).   • The amount invested in CD (4% return) should be at   least as much as the amount invested in GF.   • No more than 60% of the investment can   be in GF and EF combined.   • EF and CD combined should account for   at least 30% of your investment.   • Do not assume that you will invest all   of $100,000. This decision should be determined by your linear programming   model.   a. Formulate a linear programming model   for your investment decision. (11pts)   b. Solve the model using Excel Solver.   (6pts)   c. Without re-solving the problem, can   you tell what would be the effect on your annual return if GF requires a   minimum investment of $30,000? (Increase or decrease by how much? Or no   change? Why?) (3pts)   d. Suppose GF’s return is increased to   10%. Without resolving the problem, can you tell if it is optimal to invest   more in GF? What do you think is causing this? (3pts)