The principal of the time value of money is probably the single most important concept in financial management. One of the most frequently encountered applications involves the calculation of a future value. The process for converting present values into future values is called knowledge of the values of three of four time-value-of-money variables. Which of the following is not one of these variables? This process requires O The inflation rate indicating the change in average prices O The duration of the investment (N) O The present value (PV) of the amount invested O The interest rate (I) that could be earned by invested funds