# The following distribution shows the daily pocket allowance of children of a locality. The mean pocket allowance is 18 rupees. Find the missing frequency f.

## Solution :

We have,

So, Mean ($$\bar{x}$$) = $$\sum f_ix_i\over f_i$$ = $$752 + 20f\over 44 + f$$

$$\implies$$ 18 = $$752 + 20f\over 44 + f$$

$$\implies$$ 752 + 20f = 792 + 18f

$$\implies$$ 2f = 40

$$\implies$$ f = 20

Hence, the missing frequency is 20.