1. Use the cash flow given and a MARR= 10% to find the following: (25 points) Year 0 1 Net Cash Flow, -18050 50 50 50 50 -70 $ a) Determine the number of possible rate of return values in the net cash flow series using the two sign tests. b) Find the rate or rates of return values with excel using interest between -50 and 50% and plot your results