Standard Deviation

Standard Deviation	September 1st, 2011
	math `[html]`

Standard deviation is the average distance between each data point and the mean of the data. It's defined as:

Why isn't it:

That is, why is it the square root of the average of (x-mu)^2 instead of just the average of |x-mu|? How is the squared version more useful?

Update 2011-09-01 I had left out the square root on the standard deviation.

←

Flavors of Utilitarianism Cryonics

→

Comment via: google plus, facebook

Recent posts on blogs I like:

Collections: Iron, How Did They Make It? Part I, Mining

This week we are starting a four-part look at pre-modern iron and steel production. As with our series on farming, we are going to follow the train of iron production from the mine to a finished object, be that a tool, a piece of armor, a simple nail, a w…

via A Collection of Unmitigated Pedantry September 18, 2020

Learning Game

I came up with this game. In the game one person thinks of something and then gives the other person a clue. And the other person writes a guess down on a blackboard or a piece of paper. Or really anything you have that's laying around that's av…

via Lily Wise's Blog Posts September 17, 2020

Hong Kong Construction Costs

I think we have found the #2 city in urban rail construction costs, behind only New York. This is Hong Kong, setting a world record for the most expensive urban el and encroaching on Singapore for most expensive non-New York subway. As we look for more da…

via Pedestrian Observations September 16, 2020

More Posts