As instructor grades exams, 30%; term paper, 20%; and final exam, 50%. a student had grades of 75,80, and 85, respectively, for exams, term paper, and final exam. find the students final average. use the weighted mean. round your answer to one decimal place.
the students final average is

Okay, so 75 counts for 30% (exams), 80 counts for 20% (term paper), and 85 counts for 50% (final exam)

So you would multiply 30% by 75, 20% by 80, and 50% by 85. That would be 22.5, 16, and 42.5. Add these numbers up, and put them over the total percentage, 100%. So you would have 81/100. The student's final average is 81%.