Shawn Bixby borrowed $25,000 on a 120-day, 15% note. After 60 days, Shawn paid $2,800 on the note. On day 96, Shawn paid an additional $4,800. Use ordinary interest. a. Determine the total interest use the U.S. Rule. (Do not round intermediate calculations. Round your answer to the nearest cent.)

Total interest $

b. Determine the ending balance due use the U.S. Rule. (Do not round intermediate calculations. Round your answer to the nearest cent.)

Ending balance due $