Please read the scenario and help me with answers for my spreadsheet. I have a couple questions in particular about the depreciation rate (is it correct)? Im not sure because the book value is negative in year 7 and 8...

Is this project worth doing? The market premium is 6% and the risk-free rate is 3.5%. (your opinion)

I just need to make sure my spreadsheet is correct and I can write the analysis on my own.