Re: Puzzled by the "Variance"

*To*: mathgroup at smc.vnet.net*Subject*: [mg86515] Re: [mg86506] Puzzled by the "Variance"*From*: George Woodrow III <georgevw3 at mac.com>*Date*: Thu, 13 Mar 2008 04:29:07 -0500 (EST)*References*: <200803121029.FAA17511@smc.vnet.net>

Variance properly has (n-1) in the denominator, to account for one fewer degrees of freedom. george On Mar 12, 2008, at 6:29 AM, Elements wrote: > 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 > >

**References**:**Puzzled by the "Variance"***From:*Elements <philyer@gmail.com>