Sample vs. population
Population variance divides squared deviations by n. Sample variance divides by n − 1 to estimate population variance from a sample. The calculator always shows both and highlights your selected convention.
Turn a raw data set into a full descriptive-statistics report: center, spread, quartiles, outliers, shape, percentiles, frequency table, histogram and box plot — with sample/population choices made explicit.
Commas, spaces, tabs, semicolons and new lines work. Spreadsheet columns paste directly. Invalid tokens are rejected instead of silently ignored.
One row per value. Frequencies must be positive whole numbers. This mode is useful for grouped classroom tables and repeated measurements.
Bars show counts; mean and median are marked.
Whiskers stop at the most extreme non-outlier values under the 1.5×IQR rule.
Uses the selected sample/population SD for z-score.
| Value | Count | Share | Cumulative |
|---|---|---|---|
| Calculate to see frequencies. | |||
Same values for everyone on the date. Estimate the requested statistic, then check yourself.
Which answer is correct?
Population variance divides squared deviations by n. Sample variance divides by n − 1 to estimate population variance from a sample. The calculator always shows both and highlights your selected convention.
Different textbooks and software can disagree on Q1/Q3. Choose inclusive linear interpolation, Tukey median-of-halves, or an exclusive (n+1) rule; the selected method is stated beside the report.
Skewness summarizes asymmetry. Excess kurtosis compares tail/peak behavior with a normal distribution baseline of 0. Small data sets can make both unstable, so interpret them cautiously.
Everything runs locally. Raw mode accepts up to 100,000 values; frequency mode expands up to 200,000 observations. This is a descriptive-statistics learning tool, not a replacement for a validated statistical package in regulated or high-stakes analysis.