If in a class of 20 students, 5 students have scored 76 marks, 7 students have scored 77 marks and 8 students have scored 78 marks, then compute the mean of the class.

GIVEN: total no of students = 20

5 students have scored 76 marks


7 students have scored 77 marks


8 students have scored 78 marks


FORMULA USED: Arithmetic mean =


Number of students = 20


Sum of marks = (5×76) + (7×77) + (8×78)


= 380 + 539 + 624


= 1543


Arithmetic mean =


Arithmetic mean = = 77.15


CONCLUSION: Arithmetic Mean of marks of class is 77.15


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