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. `Ag e (i n years)                     Number of policy holders` `Below 20                          2` `Below 25                          6` Below 30                          24 Below 35                          45 Below 40                          78 Below 45                          89 Below 50                          92 Below 55                          98 Below 60                          100

Explanation

it can be observed that
`n = 100 ⇒ n/2 = 50`

Cumulative frequency (cf) just greater than 50 is 78, belonging to class-interval `35 − 40`
Therefore, median class = `35 - 40`

Class size, h = 5
Lower limit of median class, `l = 35`
Frequency of median class, `f = 33`
Cumulative frequency of class preceding median class, `cf = 45`

Median `= l + [(n/2 - cf)/f] xx h`

`= 35 + [(50 - 45)/33] xx 5`

`= 35 + 25/33`

`= 35 + 0.76`

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