3. Two sections of a class took the same quiz. Section A had 15 students who had a mean score of 80, and Section B had 20 students who had a mean score of 90. Overall, what was the approximate mean score for all of the students on the quiz? A) 85.7 D) None of these B) It cannot be determined. E) 85.0 C) 84.3 4 A professor has kept records on grades that students have earned in his class. If he