question_answer

  Find the median from :

Marks	0-10	10-30	30-60	60-80	80-100
Frequency	5	15	30	8	2

Answer:

  Here, the class intervals are of unequal width. If the class intervals are of unequal width, the frequencies need not be adjusted to make the class intervals equal.  

Marks	No of students (Frequency)	Cumulative frequency
0-10 10-30 30-60 60-80 80-80	5 15 30 8 2	5 20 50 58 60

Here,            N = 60  N/2 = 30 The cumulative frequency just greater than N/2 = 30 is 50 and the corresponding class is 30-60. Hence, 30-60 is the median class. Now, Median