Question

Find the median of the following frequency distribution :
Class
10-20
20-30
30-40
40-50
50-60
60-70
70-80
80-90

Frequency
9
11
15
24
19
9
8
5

Answer 1

Here ,

n = 100,

n/2 = 100/2 = 50 ,

Now , 40 - 50 is the class whose

cumulative frequency is greater

than 50 .

Therefore ,

40 - 50 is the median class,

Now ,

l = 40 , n = 100,

cf = 35 ,

f = 24 ,

h = 10 ,

Median = l + [ (n/2 - cf )/f ] × h

= 40 + [ (50 - 35 )/24] × 10 }

= 40 + ( 15/24 ) × 10

= 40 + 6.25

= 46.25

Therefore ,

Median = 46.25

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