Question

Draw 'less than' type cumulative frequency curve and find the median from the following table

Marks Scored	Number of Students
Below $20$	$6$
Below $40$	$10$
Below $60$	$20$
Below $80$	$36$
Below $100$	$50$

Answer 1

Class Interval (Marks Scored)	Cumulative frequency (Less than type) ($F_i$)	Upper boundary ($u_i$)	Points plotting ($u_i,f_i$)
-	0	0	(0, 0)
0-20	6	20	(20, 6)
20-40	10	40	(40, 10)
40-60	20	60	(60, 20)
60-80	36	80	(80, 36)
80-100	50	100	(100, 50)
Total	N = 50

Here, $N=50$
$\frac{N}{2}=\frac{50}{2}=25$
Through mark 25 on y axis, draw a horizontal line which meets the graph at point A.
Then through point A, draw a vertical line which meets x axis at the mark 66
$\therefore$ Median = 66