a professor teaches 3 sectionof introductory stats. resultsof the midterm :

a professor teaches 3 sectionof introductory stats.

resultsof the midterm :

section   # students writing exams    mean gradeof students writing exams(%)

1                      50                                               55

2                     30                                               68

3                    20                                                75

calculate the combinedgradeof all the students writing exams

plse respond ASAP thanks

Recall that mean = sum of scores divided by number of scores ⇒ sum of scores =frequency * meanSum of scores of class 1 = 50*55 = 2750Sum of scores of class 2 = 30*68 = 2040Sum of scores of...