Shawn Bixby borrowed $27,000 on a 180 -day, 11% note. After 80 days, Shawn paid $3,000 on the note. On day 118 , Shawn paid an additional $5,000. Use ordinary interest. a. Determine the total interest use the U.S. Rule. Note: Do not round intermediate calculations. Round your answer to the nearest cent. Answer is complete but not entirely correct. b. Determine the ending balance due use the U.S. Rule. Note: Do not round intermediate calculations. Round your answer to the nearest cent