Discount Rate - Example Twelve years ago, Jake invested $2,000. Six years ago, Tami invested $4,000. Today, both Jake's and Tami's investments are each worth $9,700. Assume that both Jake and Tami continue to earn their respective rates of return. (1) What is annual interest rate that Jake has earned? (2) What is annual interest rate that Tami has earned? (3) Was Tami's investment worth more than Jake one year ago? 1.23