Question

The median of the following distribution is 35, find the values of a and b.
C.I : 0–10 10–20 20–30 30–40 40–50 50–60 60–70 ,
f : 10 20 a 40 b 25 15 total 170

Answer 1

SOLUTION IS IN THE ATTACHMENT.
Median:
Median is that value of the given observation which divides it into exactly two parts.

MEDIAN for the GROUPED data :

For this we find the Cumulative frequency(cf) of all the classes and n/2 , where n =  number of observations.

Now find the class whose Cumulative frequency is greater than and nearest to n/2 and this class is called median class,then use  the following formula calculating the median.

MEDIAN = l + [(n/2 - cf )/f ] ×h

Where,
l = lower limit of the median class
n = number of observations
cf = cumulative frequency  of class interval preceed the  median class
f = frequency  of median class
h = class  size

HOPE THIS WILL HELP YOU...

Answer 2

Answer:

a = 35 and

b = 25

Hope the image is clear. Thank you.