Statistics Quick-Read
Mean, median, mode, range, variance, and standard deviation (sample and population) for a list of numbers.
Example
You enter
- Numbers (comma or whitespace separated) 2, 4, 4, 4, 5, 5, 7, 9
You get
- Count 8
- Mean 5
- Median 4.5
- Sample standard deviation (n-1) 2.138
Checked against published worked examples from: Standard descriptive statistics (classical).
Details, formula, and sources
Formula or tableStandard descriptive statistics. mean = sum / n; sample variance = sum((x_i - mean)^2) / (n-1); population variance = sum((x_i - mean)^2) / n; standard deviation = sqrt(variance).
Source and editionClassical descriptive statistics; physical / mathematical fact. The sample-vs-population distinction is the Bessel-correction convention (Bessel 1838).
Free accessNo code citation required. Any introductory statistics text covers these.
What governsEstimate only. Readability formulas and similar metrics are derived from a representative population and have known edge-case noise. The classroom teacher governs final text selection, grade placement, and assessment decisions.
API field namesvalues, count, mean, median, sd_sample
- Input parsing comma or whitespace separated tokens; non-numeric tokens are silently skippedconvention
- Mode all values tied for highest frequency; empty list when every value is uniqueconvention