Susie deposits $1500 into an account today and then $1000 into the account 10 years later. Assume that interest is credited to the account at a nominal annual interest rate of i^(6), convertible every two months, for the first 5 years, and at a nominal discount rate of 10%, compounded quarterly, thereafter. The accumulated balance in the fund after the 20 years is $10,000. Find i^(6).