Calculate the mean of the scores of 20 students in a mathematics test
We first, find the class mark xi of each class and then proceed as follows
Therefore, mean 
Hence, the mean of scores of 20 students in mathematics test 35.
2
Calculate the mean of the scores of 20 students in a mathematics test
We first, find the class mark xi of each class and then proceed as follows
Therefore, mean
Hence, the mean of scores of 20 students in mathematics test 35.