The Continental Bank made a loan of $31,000.00 on March 18 to Dr. Hirsch to purchase equipment for her office. The loan was secured by a demand loan subject to a variable rate of interest that was 8% on March 18. The rate of interest was raised to 8.6% effective July 1 and to 9.2% effective September 1. Dr. Hirsch made partial payments on the loan as follows: $800 on May 24; $900 on June 29; and $300 on October 19. Each payment is first applied to any accumulated interest. Any remainder is then used to reduce the outstanding principal. The terms of the note require payment on October 31 of any interest not paid off by partial payments. How much must Dr. Hirsch pay on October 31? Dr. Hirsch must pay $ on October 31. (Round the final answer to the nearest cent as needed. Round all intermediate values to six decimal places as needed.)