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. b. You should find that the optimal solution is not integer-valued. If you round the values in the changing cells to the nearest integers, is the resulting solution still feasible? If not, how might you obtain a feasible solution that is at least close to optimal