What descriptive statistics tell you
Descriptive statistics summarise a data set in a handful of numbers instead of a long list. They fall into three groups: measures of centre (mean, median, mode) that show where the data sits, measures of spread (standard deviation, variance, range, IQR) that show how scattered it is, and measures of position (minimum, quartiles, maximum) that show the shape of the distribution.
Reading the summary
- If the mean and median are close, the data is fairly symmetric; a big gap suggests skew or outliers.
- A large standard deviation relative to the mean means the values are widely spread.
- The IQR (Q3 − Q1) captures the middle half of the data and ignores extremes, making it robust to outliers.
Frequently asked questions
Which quartile method does this use?
The inclusive, linear-interpolation method that matches Excel's QUARTILE.INC and PERCENTILE.INC.
Should I pick sample or population?
Use sample (the default) when your data is a subset of a larger group; population when it covers the entire group. It only changes variance and standard deviation.
Can I copy the whole table?
Yes — the "Copy all" button copies every statistic as label-and-value pairs, ready to paste into a document or spreadsheet.