Waiting periods. Fill in the number of periods for the following table, E , using one of the three methods below: In (FV/PV) a. Use the waiting period formula, n= In (1 + r) b. Use the TVM keys from a calculator. c. Use the TVM function in a spreadsheet. Present Value $ 805.65 Future Value 1,640.37 Interest Rate 5% Number of Periods years (Round to the nearest whole number.)