I am having trouble completing number 4. I am supposed to find the payback period (1) & the net present value after the tax hurdle rates of 10%, 12% and 14% (2).

I was able to calculate part 1 for number 4: 134,400/28,000 = 4.8 years for the payback period.

The management of Niagara National Bank is considering an investment in automatic teller machines. The machines would cost $124,200 and have a useful life of seven years. The bank's controller has estimated that the automatic teller machines will save the bank $27,000 after taxes during each year of their life (including the depreciation tax shield). The machines will have no salvage value. Required: 1. Compute the payback period for the proposed investment. 2. Compute the net present value of the proposed investment assuming an after-tax hurdle rate of (a) 10 percent, (b) 12 percent, and (c) 14 percent. 3 4. Build a spreadsheet: Construct an Excel spreadsheet to solve requirements 1 and 2 above. Show how the solution will change if the following information changes: the machines would cost $134,400, and the annual savings amount to $28,000