Mean symbol
The mean symbol x̄ — “x-bar” — is not a letter on any keyboard: it is the letter x wearing a bar built from a second, invisible character. That trick is why students and report-writers come here to copy it. This page gives you x̄ ready-made, its population twin μ, and the standard deviation symbol σ that travels with it.
Copy the statistics notation
Notation ready to copy
Mean vs standard deviation — sample vs population
| Symbol | Means | When it is used |
|---|---|---|
| x̄ | Sample mean | The average of the data you actually collected |
| μ | Population mean | The average of the whole group, known or theoretical |
| s | Sample standard deviation | The spread around x̄ in your sample |
| σ | Population standard deviation | The spread around μ — THE standard deviation symbol of textbooks |
| σ² | Variance | The standard deviation squared — spread in squared units |
The bar is a combining character (U+0304): it glues itself onto the letter before it, which is why x̄ is really two characters holding hands. Copying the pair from this page keeps them together; typing it yourself means adding the bar as a separate step, below.
How to type x̄
| Platform | Method |
|---|---|
| Word | Type x, then 0304 and Alt + X (the code becomes the bar over the x) — or Insert → Equation and use \bar{x} |
| Excel / Sheets | No x-bar keystroke: compute with AVERAGE(), and paste x̄ from here as the label |
| LaTeX | \bar{x} for a sample mean; \mu and \sigma for its partners |
| HTML | The letter x followed by combining macron code 772 — or paste the pair |
Explore more
The summation partner Σ works the totals on the math symbols hub with the whole operator family, and every sign’s name is listed in the symbol names and meanings guide.
Frequently asked questions
How do you read x̄ out loud?
“x-bar”. The bar is statistics’ way of saying “the average of all the x values” without writing the words — one symbol for a whole computation.
What is the standard deviation symbol?
σ — Greek small sigma — for a population, and s for a sample. It measures spread: how far values typically sit from the mean. Small σ, tight cluster; large σ, scattered data.
Why does my pasted x̄ sometimes lose its bar?
The bar is a separate combining character; a few older apps and fonts drop or misplace it. It survives in Word, browsers, phones and modern documents — if your app mangles it, an equation editor (\bar{x}) is the robust route.
Is x̄ the same as μ?
Same idea, different scope: x̄ is the mean of your sample (data in hand), μ the mean of the whole population (often unknown, estimated by x̄). Reports keep them apart for honesty.
What does x̄ ± σ mean?
“The mean, give or take one standard deviation” — the quickest honest summary of a dataset: centre and spread in four characters.