An Ode To Italian-Americans

[johnwesley73]

I was trying to phrase a reply to Vincent's entry re IQ tests and was rummaging around some Charles Murray citations when it struck me that what I wanted to say couldn't be summed up in one little reply post

Comments

[curiouscliche]

A standard deviation is the square root of the variance for a given sample of data. Variance is determined by subtracting each datum from the average of the sample as a whole, squaring that difference (to compensate for negative differences), and then adding them all up. Then dividing by the number of individual datum in the sample.

Basically standard deviation tells you the average amount of difference between any given datum in the sample, and the average of the data as a whole.