Re: The sample s.d. always underestimates


"Luis A. Afonso" wrote, in reply to Jack Tomsky:

_1__The goal is to compare the Distribution Variance with the Sample Variance. You are failing the goal because you did not define the Distribution you are dealing with.

Afonso, can't you understand simple English as in Jack's first line
below?

Jack> The sample variance depends only on the sample, not the cdf.
Jack> x(1) and x(2) are realizations from a sample of size two.

Jack's example was one of infinitely many COUNTEREXAMPLES
to your erroneous statement.


Do you got my *exasperation*?

_____licas (Luis A. Afonso)

I think by now, for ANYONE who has read just ONE of the dozen or
so corrections others made about your ERROR, or even if the
person had read ONLY your posts on this subject, that person
would have been thoroughly convinced not only of your total
ignorance in statistics, but the lack of any redeeming value in
ANY of your posts.

-- Reef Fish Bob.

.

Relevant Pages

  • Re: Do you want it?
    ... alter the fact that they are all called "sample variance", ... You should snip that line from your sig file. ... Twice used by Jack the OP. ... by Afonso and others, you'll be treated equally, in order for the ...
    (sci.stat.math)
  • Re: Luis Afonso #3 not sure WHICH program Jack referenced when there was ONLY ONE!
    ... Luis, in your simulation, you are assuming that the true variance of p1* - p2* ... Jack, please, send me the program´s name you are referring to, in order to find it in my archives. ... you ask Afonso about it, that Literary GIANT among Afonsos ... RF> even know how to compute the sample variance of 400,000 numbers ...
    (sci.stat.math)
  • ANYONE who does NOT follow the 4-line example, please SPEAK UP.
    ... Obviously I DIDN'T write that horrendous English Afonso wrote, ... Let be the example Bob chose to *prove* I was wrong ... LAA> the SAMPLE variance is always <= the POPULATION variance. ...
    (sci.stat.math)
  • SIX "Is this sufficiently clear" questions for Luis A. Afonso to answer
    ... This is also IRRELEVANT to your LAAF. ... We should not, in any instances, make confusion between the Sample Variance and the UNBIASED ESTIMATE of the Population variance - are rather different things. ... Luis A. Afonso asked Kevin ...
    (sci.stat.math)
  • Re: Difference b/w Standard Deviation and Variance
    ... At least Afonso is trying to talk statistics when he made his error ... __the SAMPLE STANDARD DEVIATION is its squared root. ... IF I WANT, based on the sample items, to have an UNBIASED ESTIMATION of the POPULATION VARIANCE we must divide the sum of the squared deviations not by N but by N-1. ... an insignificant number of authors chose to define ABUSIVELY the sample variance using N-1. ...
    (sci.stat.math)
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