Math & Algebra
Standard Deviation
Sample SD (n−1).
Educational estimates only. Not medical, legal, tax, or financial advice.
Guide: Standard Deviation
What it does
Calculates mean, variance, and sample SD with n−1 denominator.
How to use it
Paste or enter numbers, then calculate.
Formula
s = √(Σ(x−x̄)²/(n−1)) for sample SD.
Example
Data 2,4,6 → mean 4, sample SD ≈ 2.
FAQs
Sample vs population SD?
Sample uses n−1; population uses n. Check which mode the tool uses.
Outliers?
SD is sensitive to outliers; consider robust measures for heavy-tailed data.
Single value?
SD is undefined or zero with one point; enter at least two values.