A life insurance agent found the following data for distribution of ages of 100 policy holders. Calculate the median age, if policies are only given to persons having age 18 years onwards but less than 60 years.
Age in years Number of policy holders
Blow 20 2
Blow 25 6
Blow 30 24
Blow 35 45
Blow 40 78
Blow 45 89
Blow 50 92
Blow 55 98
Blow 60 100
Answers
The median age, if policies are only given to persons having age 18 years onwards but less than 60 years is 35.76.
Given,
Age in years Number of policy holders
Blow 20 2
Blow 25 6
Blow 30 24
Blow 35 45
Blow 40 78
Blow 45 89
Blow 50 92
Blow 55 98
Blow 60 100
we have,
Age in years Number of policy holders (fi) Cumulative freq (cf)
0 - 20 2 2
20 - 25 6-2=4 2+4=6
25 - 30 24-6=18 6+18=24
30 - 35 45 -24=21 24+21=45
35 - 40 78 -45=33 45+33=78
40 - 45 89 -78=11 78+11=89
45 - 50 92 -89=3 89+3=92
50 - 55 98-92=6 92+6=98
55 - 60 100-98=2 98+2=100
∑ fi = 100
N = 100
N/2 = 100/2 = 50
The median class is 35 - 40
where,
l = lower limit of median class = 35
h = class interval = 40-35 = 5
cf = cumulative frequency of median class = 45
f = frequency of median class = 33
Median = 35 + ( 50 - 45 )/ 33 * 5
= 35 + 5 / 33 * 5
= 35 + 25 / 33
= 35.76