Rex Electric has decided to move into low-rise (2 to 8 floors) commercial building electrical wiring. After great successin upscaie residential and small commercial wiring, they have identified four independent and indivisible investments any of all af which will help make the move to the next leyel. Rex Electric's MARR is 10%, and $500,000 is available for investinent immedistelf, with $175,000 available for follow-up investment the ned year. The canh fows areshown below. Using SOLVER for sensitivity analysis: Determine the optimum portfolio and its PW using (1) the current limit on investment capital, (2) plus 20% to the year 0 limit and (3) minus 20% to the year 0 limit. (1) PW:S (2) PW:\$ (3) PW:S