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Puzzled by the "Variance"

  • To: mathgroup at smc.vnet.net
  • Subject: [mg86506] Puzzled by the "Variance"
  • From: Elements <philyer at gmail.com>
  • Date: Wed, 12 Mar 2008 05:29:07 -0500 (EST)

Greeting all
I'm puzzled by the function "Variance". We can learn how to calculate
variance from this page:http://mathworld.wolfram.com/SampleVariance.html.
For example, calculate the sample variance of {1,2,3}. the average of
{1,2,3} is 2, then the variance should be ((1-2)^2+(2-2)^2+(3-2)^2)/3=2/3.
But mathematica gives that:

In[10]:= Variance[{1.0,2.0,3.0}]
Out[10]= 1.

Why??
-- 
Best Wishes!
Yours Sincerely



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