Question

Obtain the A.M of the following data.

Marks	$65$	$70$	$75$	$80$	$85$	$90$	$95$	$100$
Number of students	$6$	$11$	$3$	$5$	$4$	$7$	$10$	$4$

Answer 1

Marks$\left(x\right)$	Number of students$\left(f\right)$	$fx$
65	6	390
70	11	770
75	3	225
80	5	400
85	4	340
90	7	630
95	10	950
100	4	400
Total	50	4105

Then, arithmetic mean=$\frac{\Sigma fx}{\Sigma f}=\frac{4105}{50}=82.1$