Question

find the missing frequency in the following distribution it is given that median of the distribution is41.50 and total number is 100persons​

Answer 1

Step-by-step explanation:

Let the missing frequency be x.

Age in years

(x) No. of persons

(f) C.F.

0-10 5 5

10-20 25 30

20-30 x 30 +x

30-40 18 48 +x

40-50 7 55 +x

N=55+x

As, N=55+x ⇒

2

N

=

2

55+x

Median=l+

f

2

N

+C

×h

As median is given 24, therefore median class is 20−30.

Therefore,

l=lower limit of median class =20

C=C.F. of the class preceding the median class =30

h= higher limit - lower limit =40−30=10

f=frequency of median class =x

∴median=20+

x

2

55+x

−30

×10

24=20+

2x

x−5

×10

4=

x

x−5

×5

⇒4x=5x−25

⇒x=25

Hence, the missing frequency is 25.