GRE Data Analysis
Descriptive statistics, distributions, probability, and counting methods. It is the content area where a correct calculation most often answers the wrong question, because mean, median and mode describe different things and the GRE asks which one moved.
Mean, median, and what separates them
| Measure | Is | Moved by an outlier |
|---|---|---|
| Mean | The total divided by the count | Strongly |
| Median | The middle value in order | Barely |
| Mode | The most frequent value | Not at all |
| Range | Largest minus smallest | Entirely |
A large share of these questions turn on exactly this: add one very large value and the mean jumps while the median moves one place. Quantitative Comparison questions are built on the gap.
- Standard deviation measures spread. Adding the same number to every value leaves it unchanged; multiplying every value scales it.
- Evenly spaced sets have mean equal to median, which turns some long calculations into one line.
Probability and counting
- Probability is favourable over total, always between 0 and 1.
- "At least one" is almost always easier as 1 minus the probability of none.
- Combinations when order does not matter; permutations when it does. Deciding which is most of the question.
- Independent events multiply; mutually exclusive events add.
Where a counting question seems to need a formula you cannot recall, list the possibilities. GRE counting questions are small enough that enumeration usually finishes inside the time a half-remembered formula would take.
Data Analysis — FAQs
2 questions
Almost never. Questions ask whether it rises, falls or stays the same, which is reasoning about spread.
Data Interpretation is the chart-based part of Data Analysis. The statistics here are what those questions apply.
More quantitative question types
Sources
Written from the test board's own published material and checked on 1 October 2026.