please help solving part B thank you

Key Results: Appralsal of the Proposed Project ionsidering equal percentage changes, the NPV appears LEAST sensitive to changes in which of these three varlables? b. Now conduct a sensitlvity analysis to determine the sensitivity of NPV to changes in the sales price, varlable costs per unit, and number of units sold. Set these varlables' values at 10% and 20% above and below their base-case values. Include a graph In your analysis. Note: The graph should resemble Figure 11-3 in the text (1.e., straight linesI) when completed. I have left some correct answers in here to help you callbrate your own answers. To fill in the blanks in this tablo, go to the top of the spreadsheet and change your assumed value, . then note the change in NPV and record the new value in these sensitlvity tablos. The graph and summary table below it should fill automatically for you. Webrnaster.com has developed a powerful new server that would be used for corporations' Internet activities. It would cost $10 million at Year 0 to buy the equipment necessary to manufacture the server. The project would require net working capital at the beginning of each year in an amount equal to 10% of the year's projected sales; for example, NWC0=10%(Sales1). The servers would soll for $24,000 per unit, and Webmasters believes that variable costs would amount to $17,500 per unit. After Year 1, the sales price and variable costs will increase at the inflation rate of 3%. The company's nonvariable costs would be $1 million at Yoar 1 and would increase with inflation. The server project would have a life of 4 years. If the project is undertaken, it must be continued for the entire 4 years. Also, the project's returns are expected to be highly corrolated with returns on the firm's other assets. The firm believes it could sell 1,000 units per year. The equipment would be depreciated over a 5-year period, using MACRS rates. The estimated market value of the equipment at the end of the project's 4-year life is $500,000. Webmasters' federal-plus-state tax rate is 40%. Its cost of capital is 10% for average-risk projects, defined as projects with a coefficient of variation of NPV betwoen 0.8 and 1.2. Low-risk projects are evaluated with a WACC of 8%, and high-risk projects at 13%