On 9/03/2010, at 12:13 PM, casperyc wrote:
>
> Hi all,
>
> I am REALLY confused with the variance right now.
You need to learn the difference
(a) Between sample variance (*estimate* of population variance)
and
population variance.
and
(b) Between discrete and continuous distributions.
Given that you understand those differences you will see that all three
answers are correct.
cheers,
Rolf Turner
>
> for a discrete uniform distribution on [1,12]
>
> the mean is (1+12)/2=6.5
> which is ok.
>
> y=1:12
> mean(y)
>
> then var(y)
> gives me 13
>
> 1- on http://en.wikipedia.org/wiki/Uniform_distribution_%28discrete%29 wiki
> the variance is (12^2-1)/12=143/12
>
> 2-
> http://www.solvemymath.com/online_math_calculator/statistics/continuous_distributions/uniform/param_uniform.php
***LOOK*** at the above. Does it or does it not contain the string
``continuous_distributions''??? And doesn't your question involve
the ***discrete*** uniform distribution???
R. T.
> here
> which used (12-1)^2/12=121/12
>
> all different 3 answers!!!
>
> All I am looking for is the variance of a random variable from discrete
> uniform distribution.
>
> Can someone clearify that for me please?
>
> Thanks.
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