[tempay]

This page is likely more approachable:

https://en.wikipedia.org/wiki/68%E2%80%9395%E2%80%9399.7_rul...

[sundarurfriend]

I thought you were going to link to https://simple.wikipedia.org/wiki/Standard_deviation

The "Simple English Wikipedia" is a really underrated resource for understanding jargon outside your field.