Answer:
81.29%
Explanation:
 Exam = 50%; 
Quiz = 30%, 
HW = 15% and PART = 5% 
 81.3% on exams, 73.8% quiz, 
90% HW and 100% 
 therefore,
 Exam total = 50×0.813 = 40.65% earned 
 Quiz = 300.738 = 22.14% earned 
 HW = 15×0.9 = 13.5 earned 
 PArt = 5×1 = 5% earned
 Total earned = 40.65+ 22.14 + 13.5+ 5 = 81.29%