Question

The following table given the weekly of workers in a factory: 

Weekly wages (in Rs)	No.of workers
50-55	5
55-60	20
60-65	10
65-70	10
70-75	9
75-80	6
80-85	12
85-90	8

Calcculate: (1)the mean, (2) the model class, (3) th number of workers getting weekly qages below Rs. 80 and (4) the number of workers getting Rs. 65 or more but less than Rs.85 as weekly wages.

Answer 1

Weekly Wages (in Rs )	No.of Workers (f)	Cumlative Frequency	Class marks (x)	fx
50-55	5	5	52.5	262.5
55-60	20	25	57.5	1150.0
60-65	10	35	62.5	625.0
65-70	10	45	67.5	675.0
70-75	9	54	72.5	652.5
75-80	6	60	77.5	465.0
80-85	12	72	82.5	990.0
85-90	8	80	87.5	700.0
Total	80			5520.0

(1)Mean= `(Σ f_x)/(Σ f)=5520/80=69`  

(2)Model class = 55 - 60 as it has maximum frequencies. 

(3)Number of workers getting wages below Rs.80 = 60 

(4)Number of workers getting Rs. 65 or more and less than Rs.85 = 72 - 35 = 37