a.) Plot the PW equation against the unknown IRR (i*) in the
range from 5% to 100%. Use a software (e.g. Excel) to do the graph.
b) Solve the PW equation for IRR by trial and error, using an
initial value (i_0) from the graph a).
Year 0 1 2 3
Cash Flow -20,000 15,000 15,000 -2,000