Hello, how do I solve c) ?

The school board for the Bellevue School District has made the decision to purchase 1,350 additional Macintosh computers for computer laboratories in all its schools. Based on past experience, the school board also has directed that these computers should be purchased from some combination of three companies-Educomp, Macwin, and McElectronics. In all three cases, the companies charge a discounted variable cost per computer and a fixed delivery and installation cost for these large sales to school districts. The next table shows these charges as well as the capacity (the maximum number of computers that can be sold from the limited inventory) for each of the companies. Capacity Fixed cost Variable Educomp 700 $45,000 Macwin 700 $35,000 McElectronics 1,000 $50,000 cost $750 $775 $700 The school board wants to determine the minimum-cost plan for meeting its computer needs. a. Formulate a BIP model in algebraic form for this problem. b. Formulate and solve this model on a spreadsheet. C. Now suppose that Macwin has not submitted its final bid yet, so the per computer cost is not known with certainty. Generate a parameter analysis report with Analytic Solver to show the optimal order quantities and total cost of the optimal solution when the cost per computer for Macwin is $680, $690, $700, $710, ..., $790, or $800