8. Retirement Planning with Net Present Value. Consider again Lindsay’s investment in Problem 7. The real value of Lindsay’s account after 30 years of investing will depend on inflation over that period. In the Excel function 5NPV(rate, value1, value2, . . .), rate is called the discount rate, and value 1, value 2, etc. are incomes

(positive) or expenditures (negative) over equal periods of time. Update your model from Problem 7 using the NPV function to get the net present value of Lindsay’s retirement fund. Construct a data table that shows the net present value of Lindsay’s retirement fund for various levels of return and inflation (discount rate). Use a data table to vary the return from 0% to 12% in increments of 1% and the discount rate from 0% to 4% in increments of 1% to show the impact on the net present value.

(Hint: Calculate the total amount added to the account each year, and discount that stream of payments using the NPV function.)