Comparing Data Across Categories

Many QR questions ask you to compare quantities across different categories — finding the highest, lowest, or ranked values, or determining proportional differences. These questions test your ability to extract and process data quickly. This lesson covers the systematic approach to comparison questions.

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Types of Comparison Questions

Type 1: Which Is Highest/Lowest?

Example: "Which product had the highest revenue in March?"

Method: Scan the relevant column (March revenue) and identify the largest value.

Speed Tip: For straightforward "which is highest?" questions, you can often identify the answer by visual inspection without calculating anything. If the table shows 340, 420, 295, 510, the answer is obviously 510.

Type 2: Ranking

Example: "Rank the regions by population from highest to lowest."

Method: Read all values, then order them. For 4–5 values, you can rank mentally. For more, jot them on the whiteboard.

Type 3: Which Has the Greatest Difference?

Example: "Which shop had the greatest increase in sales from January to February?"

Method: Calculate the difference for each shop, then compare. You may be able to estimate rather than calculate exactly if the differences are clearly unequal.