Complete a spreadsheet (by hand or by Excel) and then determine the after-tax internal rate of return by hand (i.e. no financial calculator or Excel routine). For this problem assume a 10-year analysis period, double declining depreciation is used, 21% corporate tax rate, an initial cost of $200,000, an annual benefit of $60,000 and no salvage value but instead you must pay a disposal fee of $20,000 that your corporate accountant determined is 100% tax deductible.