Find the mode of the daily pocket money (₹) of 64 children. Class 11–13: 7, 13–15: 6, 15–17: 9, 17–19: 13, 19–21: 20, 21–23: 5, 23–25: 4.

**Modal class**: class with HIGHEST frequency.

**Mode formula**:
**Mode = $l+h\times (f$₁ − $f$₀) / $(2f$₁ − $f$₀ − $f$₂)**

Where:
- $l$ = lower limit of modal class
- $h$ = class width
- $f$₁ = frequency of modal class
- $f$₀ = frequency of class BEFORE modal class
- $f$₂ = frequency of class AFTER modal class

**Example**: Modal class 30–40 with $f$₁ = 12, $f$₀ = 5, $f$₂ = 8. $l=30,h=10$.
Mode = $30+10\times (12-5)/(24-5-8)=30+\frac{70}{11}$ ≈ 36.36.