please using excel to solve the problem thanks

3. BMT has developed a new product. It can go into production for an initial investment of $3,000,000. The equipment will be depreciated using straight-line depreciation over 5 years to a value of zero. The firm believes that net working capital at each date will equal 20 percent of next year's forecast sales. The firm estimates that variable costs are equal to 40% of sales and fixed costs are $800,000 per year. Sales forecasts in dollars are below. The project will come to an end after 5 years, when the product becomes obsolete. The firm's tax rate is 21 percent, and the discount rate is 8 percent. Calculate the NPV. 4. In problem 3, perform sensitivity analysis on the following assumptions and find the revised NPV (a) variable costs are equal to 50% of sales (b) the discount rate is 10%