The weekly pocket money (in ₹) of a group of students is shown below, with one frequency missing.

Explanation

1. 01

   Class marks: 10, 30, 50, 70, 90.

2. 02

   $\sum fx = 50 + 240 + 50p + 840 + 630 = 1760 + 50p$, and $\sum f = 32 + p$.

3. 03

   $\frac{1760 + 50p}{32 + p} = 54$, so $1760 + 50p = 1728 + 54p$.

4. 04

   $4p = 32$, giving $p = 8$.