question_answer

  The median of the following data is . Find the missing frequencies x and y, if the total frequency is 100

Class Interval	Frequency
0-5 5-10 10-15 15-20 20-25 25-30 30-35 35-40	7 10 x 13 y 10 14 9

 

Answer:

   

C.I	Frequency	Cumulative frequency
0-5 5-10 10-15 15-20 20-25 25-30 35-40	7 10 x 13 y 14 9	7 17 17 + x 30 + x 30 + x + y 54 + x + y 63 + x + y

We have median It lies in the class interval 20-25, so 20-25 is the median class   Median Given Solving (1) and (2) we get x = 17, y = 20