1. Construct a spreadsheet to calculate the payback period, internal rate of return, modified internal rate of return (assume the investment rate is the same as the borrowing rate), profitability index and net present value of the proposed mine. 2. Based on your analysis, should the company open the mine? 3. What would your opinion be if bullock mining evaluated the risk of spending $850 million and decided in the current environment, they required a 30% required return on all of its new gold mines? why? 4. What is the meaning of the "required return??