A demand loan of $8000 is repaid by payments of $3000 atter fifteen months, $4000 after thirty months, and a final payment after four years. If interest was 8% for the first two years and 9% for the remaining time, and compounding is quarterly, what is the size of the final payment? The size of the final payment is 5 (Round the final answer to the nearest cent as needed. Round all intermediate values to six decimal places as needed.)