Numerical Reasoning
Weighted Average
Calculate averages where different values carry different weights or importance.
Overview
Weighted average questions present per-capita or per-unit data alongside population or volume data. You cannot simply average the per-capita values — you must weight each by its population.
Common scenario: "What is the average CO2 emissions per capita across France, Germany, and Poland?" You must multiply each country's per-capita value by its population, sum the results, then divide by total population.
What is tested
- Multiplying values by their weights
- Summing weighted values and total weights
- Dividing total weighted sum by total weight
- Recognizing when simple average is incorrect
Preparation tips
- Never average per-capita values directly — always weight by population
- Write out each step: value × weight for each row, then sum, then divide
- A common distractor is the simple (unweighted) average — it will always be a wrong option
- Check units: if mixing millions and thousands, convert first
Master the mathematical foundations
Every numerical reasoning question tests 2-4 mathematical concepts. Weakness in one concept means failure on every question that uses it. Review the concept library to build a solid foundation.
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