Shawn Bixby borrowed $$38,000$ on a $120-$day, $8\%$ note. After $75$ days, Shawn paid $$4,100$ on the note. On day $107,$ Shawn paid an additional $$6,100.$ 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 balano due