Quantitative Data Comparisons
Comparison questions ask you to determine which value is larger, which trend is steeper, or which proportion is greater. They appear in numerical reasoning tests and require careful reading and calculation. Here's how to approach them.
Types of Comparisons
Direct value – "Which region had the highest revenue?" Read or calculate each value, then compare. Sort mentally or write a short list.
Percentage or ratio – "Which product had the highest profit margin?" Margin = Profit ÷ Revenue × 100. Calculate for each, then compare.
Change over time – "Which division had the largest percentage increase?" Use ((New − Old) ÷ Old) × 100 for each. Compare the results.
Proportion of total – "Which category contributed the most to total sales?" Calculate each as a percentage of the total, or compare absolute values if one is clearly larger.
Strategy
Know what you're comparing – Same metric? Same time period? Same base? "Higher growth" might mean absolute increase or percentage increase—they can differ.
Calculate only what you need – If the question asks "which is greater, A or B?", you might not need exact values. Estimate: A ≈ 120, B ≈ 115 → A is greater.
Use elimination – When comparing several options, rule out clearly wrong ones first. That narrows the work.
Check units – Ensure you're comparing like with like. Revenue in £m vs £000—convert before comparing.
Common Pitfalls
- Wrong metric – "Highest sales" vs "highest growth"—different. "Largest share" vs "largest absolute value"—different.
- Wrong period – Comparing Q1 to Q2 when the question asks for full-year. Or mixing years.
- Wrong base – For "which grew faster?", use the same base (e.g. percentage change from the same starting point).
Quick Comparisons
- Fractions – To compare A/B and C/D: cross-multiply. A×D vs B×C. Larger product wins.
- Percentages – 15% of 1000 = 150. 20% of 800 = 160. So 20% of 800 > 15% of 1000.
- Percent change – Smaller base can give larger % change for the same absolute change. 10 → 20 is 100% increase; 100 → 110 is 10% increase.
Practice with numerical reasoning questions and the numerical reasoning test.
Frequently Asked Questions
How do I compare when values are close?
Calculate more precisely. Or use the difference: if A − B is positive, A > B. For percentages, compute both and compare.
What if I need to compare more than two options?
Rank them. Calculate the metric for each, then order. You might not need exact values—sometimes "A is highest" is clear from estimation.
How do I compare growth rates across different bases?
Use percentage change: ((New − Old) ÷ Old) × 100. That normalises for different starting sizes. A small division can have high % growth but low absolute growth.