Correct Answer - Option 4 : 47.39 kg
Given
Average weight of 12 students = 46.25 kg
Average weight of 18 students = 48.15 kg
Formula Used
Average = Sum of Data/Number of Data
Calculation
Average of 30 students = [(12 × 46.25) + (18 × 48.15)]/30
⇒ (555 + 866.7)/30 = 47.39 kg
∴ The average weight of all students in the class is 47.39 kg