Tom borrows $39,000 at the annual effective interest rate of 6% and agrees to repay it with 30 annual installments. Amount of payment in last 20 years is set at thrice that in first ten years. At end of ten years, Tom has choice to repay entire loan with the final payment of X in addition to regular payment then due. X is found so that lender will realize the annual effective interest rate of 6.1% over ten-year investment period. Determine X.