<a href="https://en.wikipedia.org/wiki/Normal_distribution" class="extiw" title="w:Normal distribution">Normal distribution</a> curve that illustrates <a href="https://en.wikipedia.org/wiki/Standard_deviation" class="extiw" title="w:Standard deviation">standard deviations</a> labeled with nominal height in inches of adult men in the USA.
Petter Strandmark, GliderMaven, cmglee
CC BY 2.5
<a href="//commons.wikimedia.org/wiki/File:Standard_deviation_diagram.svg" class="image"><img alt="Standard deviation diagram.svg" src="https://upload.wikimedia.org/wikipedia/commons/thumb/8/8c/Standard_deviation_diagram.svg/400px-Standard_deviation_diagram.svg.png" decoding="async" width="400" height="200" srcset="https://upload.wikimedia.org/wikipedia/commons/thumb/8/8c/Standard_deviation_diagram.svg/600px-Standard_deviation_diagram.svg.png 1.5x, https://upload.wikimedia.org/wikipedia/commons/thumb/8/8c/Standard_deviation_diagram.svg/800px-Standard_deviation_diagram.svg.png 2x" data-file-width="400" data-file-height="200"></a>