Determine the External Rate of Return for the following cash-flow, for an external reinvestment rate of 3.5% It is suggested that you use MS Excel for this problem. If you do, be sure to provide supporting information about what numbers are in each column, and if formulas are used to find a certain value, which formula was used. 13,500 10,500 7800 5500 5300 5300 10 13 2000 11,000 11,000 11,000