Question

21. The marks obtained by the students of class VII in the class test of Mathematics are given in the table below. Find the average marks. Marks obtained No. of students 10 3 20 6 30 10 40 7 50 4​

Answer 1

The average marks = 31

Explanation:

We know that the average can be measured using mean

Mean = Sum of observations / no of observations

In the given data no of observations = sum of frequencies

= 3+6+10+7+4

=30

Sum of observations = No of marks * frequency 1 + No of marks * frequency 2+...

= 10*3 +20*6+30*10+40*7+50*4

= 930

Mean = 930/30

= 31