A data set can be summarized in several ways. The mean describes an arithmetic center, the median identifies the middle position, the range covers the endpoints and standard deviation describes how widely the values spread.
By Calqoras Editorial Team • Reviewed September 1, 2026
A data set can be summarized in several ways. The mean describes an arithmetic center, the median identifies the middle position, the range covers the endpoints and standard deviation describes how widely the values spread.
Check the data before calculating
Confirm that every observation uses the same unit and belongs to the question being studied. A summary cannot repair values collected incorrectly or from an unsuitable group.
Mean and median answer different questions
The mean uses every value and can be pulled by an extreme observation. The median is the middle value after sorting and is often more representative when a distribution is strongly skewed.
Range provides a quick spread
Subtract the minimum from the maximum. The range is easy to understand but uses only two observations, so it does not explain how values are distributed between the endpoints.
Interpret standard deviation in context
Standard deviation measures spread around the mean using the original measurement unit. Population and sample formulas differ, so choose the version required by the course or analysis.
Quick reference table
| Item | Meaning or example |
|---|---|
| Mean | Sum divided by count |
| Median | Middle sorted value |
| Range | Maximum minus minimum |
| Standard deviation | Spread around the mean |
Reference and further reading
This guide is general educational information. Continue with NIST/SEMATECH Statistics Handbook and verify important figures independently.
This article is general educational information prepared by the Calqoras Editorial Team. Verify important figures independently and consult a qualified professional where appropriate.
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