A life insurance agent found the following data for distribution of ages of 100 policy holders. Calculate the median age, if policies are given only to persons having age 18 years onwards but less than 60 year.

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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