M.For a math course, we got the exam score for five students. The full credit is 10 points. The data is shown below: 8,7,7,9,10 Assume the data in the question is only a sample data and we don't think it is a good way to evaluate the students' performance. As a result, we collect the grades for the entire class. The result shows 5 students got 7 points, 6 students got 8 points and 4 students got 9 points and 2 students got 10 points. Can you use the weighted mean method to find the mean