Without considering the random variability, extend the current worksheet to 20 years. Confirm that by using the constant annual salary growth rate and the constant annual portfolio growth rate, Tom can expect to have a 20-year portfolio of $772,722. What would Tom's annual investment rate have to increase to in order for his portfolio to reach a 20-year, $1,000,000 goal? (Hint: Use Goal Seek.).
Redesign the spreadsheet model to incorporate the random variability of the annual salary growth rate and the annual portfolio growth rate into a simulation model. Assume that Tom is willing to use the annual investment rate that predicted a 20-year, $1,000,000 portfolio in part 1. Show how to simulate Tom's 20-year financial plan. Use results from the simulation model to comment on the uncertainty associated with Tom reaching the 20-year, $1,000,000 goal.