Bruce Wayne borrowed $14 300.00 for investment purposes on May 19, on a demand note providing for a variable rate of interest and payment of any accrued interest on December 31. He paid $1, 300.00 on June 28, $1, 450 on September 25, and $4, 200.00 on November 15. How much is the final payment on December 31 if the rate of interest was 11.5% on May 19; 8.21% effective August 1; and 6.35% effective November 1? use the declining balance method and show all calculations