Three new (related) pages:
How are they? Any mistooks?
Okay! Very good.
Nice example, not only informative but mouth watering also.
If it ain't broke, fix it until it is.
A number by itself is useful, but it is far more useful to know how accurate or certain that number is.
You might consider a link from Variance on the third page to your Standard Deviation and Variance page.
Children are not defined by school ...........The Fonz
You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei
You may consider adding a few lines about central moments, and tell that variance is one of those.
"Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense" - Buddha?
"Data! Data! Data!" he cried impatiently. "I can't make bricks without clay."