You still haven’t explained how the average of 85 was calculated, even though you have explained how the grade is made up: 80% for the 4 exams and 20% for homework and definitions, making 100%. 100% means that there are no other scores to be considered. If the total score is 236+200=436, the average over 3 exams and two other sections is 436/5=87.2, not 85, and 436/6=72.7, if the zero-score final exam result is included. The question still has missing details or clarification (for example, the scoring/grading method).
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