Question

The daily wages of 80 workers in a project are given below

Wages (in Rs)	400-450	450-500	500-550	550-600	600-650	650-700	700-750
No. of Workers	2	6	12	18	24	13	5

Use a graph paper to draw an ogive for the above distribution. (Use a scale of 2 cm = Rs 50 on x-axis and 2 cm = 10 workers on y-axis. Use your ogive to estimate: 

(i) the median wage of the workers.

(ii) the lower quartile wage of workers. 

(iii) the number of workers who earn more than Rs 625 daily.

Answer 1

The cumulative frequency distribution for the given data is :

Plot the points (450, 2), (500, 8), (550, 20), (600, 38), (650, 62), (700, 75), (750, 80). Join them free hand to get the required ogive.

Now, from the graph, we obtain: 

(i) median wage of the workers = Rs 605 

(ii) lower quartile wage of workers = Rs 550

(iii) Number of workers who earn more than Rs 625 daily = 80 – 50 = 30.