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The detailed guide below is currently available in English.
The full picture in one pass
Descriptive statistics answer three questions about a list. Where is its center? The mean balances all values, the median is the middle of the sorted list, and the mode is the most frequent entry. How spread out is it? Range covers the extremes, while variance and standard deviation measure typical distance from the mean — the standard deviation squares, averages, and re-roots the deviations so it lands back in the original units. And which form applies? A sample divides squared deviations by n − 1 to correct for underestimating spread, while a full population divides by n; both are printed so the choice stays yours.
よくある質問
When should I pick sample instead of population statistics?
Use the sample (s) values when your numbers are a subset of something bigger — thirty measured parts out of a production run. Use the population (σ) values only when the list is genuinely everything: all five machines in a shop.
Can there be more than one mode?
Yes. If two or more values tie for the highest frequency, all of them are modes and the results list them together — 2, 2, 5, 5, 9 is bimodal with modes 2 and 5. A list where every value appears once has no mode.