STATISTICS A4

In Mathematics test the following marks were recorded.

marks	31-40	41-50	51-60	61-70	71-80	81-90
No. of students	5	7	14	10	8	6

Calculate the mean.

Solution

Here you are required to produce the frequency distribution table.

Class interval	Class mark (x)	Frequency(f)	fx
31-40	35.5	5	177.5
41-50	45.5	7	318.5
51-60	55.5	14	777
61-70	65.5	10	655
71-80	75.5	8	604
81-90	85.5	6	513
		∑f = 50	∑fx = 3045

Mean = ∑fx

               ∑f

Mean = 3045

               50

Mean =  60.9

         

Hence Mean =  60.9