A family business has the cash flow series has presented below. Year 1 2 3 4 Revenues 30,500 24,500 9500 33,500 Costs ($) -6000 -35500 -12500 -11500 -17500 Determine the following: a) What conclusions can you draw from the Descart and Norstrom tests applied to the cash flow of the family business? b) Numerically calculate the external rate of return using the Modified ROR (MIRR) method if i = 18% per year and i, = 10% per year. c) The external rate of return using the Return on Invested Capital (ROIC) method if i = 18%.