please show formulas using excel.

Pappy's Potato has come up with a new product, the Potato Pet (they are freeze-dried to last longer). It is expected that Potato Pet will generate annual sales of $575,000 over 4 years. The fixed costs associated with this will be $179,000 per year, and variable costs will amount to 20 percent of sales. The equipment necessary for production of the Potato Pet will cost $920,000 and falls in the MACRS five-year class. It will have a salvage value of $50,000 at the end of 4 years. The equipment will require an increase in working capital (spare parts inventory) of $7,500 at the beginning. Pappy's is in a 34 percent tax bracket and has a required return of 12 percent. MACRS 5-Year Class Year 1: 20% Year 2: 32% Year 3: 19.2% Year 4: 11.52% Year 5: 11.52% Year 6: 5.76% b. 4. What if the sales level is 25% higher than the current estimate? Compute the NPV and IRR of the project. What if the sales level is 50% higher than the current estimate? Compute the NPV and IRR of the project c. What if the sales level is 25% lower than the current estimate? Compute the NPV and IRR of the project d. What if the sales level is 50% lower than the current estimate? Compute the NPV and IRR of the project