9. Exercise Problem III

The following distribution shows the daily pocket allowance of children of a locality. The mean pocket allowance is \(Rs. 18\). Find the missing frequency \(f\).

 

Daily pocket allowance (in ₹)	\(11-13\)	\(13-15\)	\(15-17\)	\(17-19\)	\(19-21\)	\(21-23\)	\(23-25\)
Number of children	\(7\)	\(6\)	\(9\)	\(13\)	\(f\)	\(5\)	\(4\)