A water treatment advisory company serving the industry, operating in Central America, presents the cash flows in dollars associated with the first three years of operation.

a) What does Descartes' Rule indicate about the changes in sign concerning the values of i*?

b) What does Norstrom's Criterion indicate?

c) Create a Net Present Value (NPV) graph (with a formula in the cell) against values of i* ranging from 0 to 100% in the Excel spreadsheet.

d) Find the real roots of the values of i* that exist for the equation TR in the Excel spreadsheet

\begin{tabular}{|c|c|c|c|c|} \hline YEAR & 0 & 1 & 2 & 3 \\ \hline Efective Net Flow $ & 16,000 & 4,000 & 64,800 & 54,400 \\ \hline \end{tabular}