difference between the the means of subsampling from an unbiased sample

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Suppose I have a distribution 𝔽 with mean M. Also, assume we have a set of i.i.d samples of size n denoted by X=$x_1,x_2,...,x_n$ from 𝔽. As a result, all $x_1,...,x_n$ are independent with identical distribution.



We know that 𝔼[X]=M.



Now suppose I derive another set of subsamples without replacement of size m from X where m ≤ n. Let's call this new subsamples Y=$y_1,y_2,...,y_m$.



Now can I say 𝔼[Y]=M?



Based on the rule of total expectation, we know that 𝔼[Y]=𝔼[𝔼[Y|X]]. I am guessing that using this law we may be able to answer yes to the previous question as the set X is not fixed.



If my claim is not correct, please give a counterexample or prove why we cannot show $ mathbbE[X]neq mathbbE[Y]$







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  • Please see this tutorial and reference on how to typeset math on this site.
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  • Thanks, is it possible for you to answer my question?
    – Infintyyy
    Jul 30 at 14:41














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down vote

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Suppose I have a distribution 𝔽 with mean M. Also, assume we have a set of i.i.d samples of size n denoted by X=$x_1,x_2,...,x_n$ from 𝔽. As a result, all $x_1,...,x_n$ are independent with identical distribution.



We know that 𝔼[X]=M.



Now suppose I derive another set of subsamples without replacement of size m from X where m ≤ n. Let's call this new subsamples Y=$y_1,y_2,...,y_m$.



Now can I say 𝔼[Y]=M?



Based on the rule of total expectation, we know that 𝔼[Y]=𝔼[𝔼[Y|X]]. I am guessing that using this law we may be able to answer yes to the previous question as the set X is not fixed.



If my claim is not correct, please give a counterexample or prove why we cannot show $ mathbbE[X]neq mathbbE[Y]$







share|cite|improve this question





















  • Please see this tutorial and reference on how to typeset math on this site.
    – joriki
    Jul 30 at 14:38










  • Thanks, is it possible for you to answer my question?
    – Infintyyy
    Jul 30 at 14:41












up vote
0
down vote

favorite
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up vote
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down vote

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Suppose I have a distribution 𝔽 with mean M. Also, assume we have a set of i.i.d samples of size n denoted by X=$x_1,x_2,...,x_n$ from 𝔽. As a result, all $x_1,...,x_n$ are independent with identical distribution.



We know that 𝔼[X]=M.



Now suppose I derive another set of subsamples without replacement of size m from X where m ≤ n. Let's call this new subsamples Y=$y_1,y_2,...,y_m$.



Now can I say 𝔼[Y]=M?



Based on the rule of total expectation, we know that 𝔼[Y]=𝔼[𝔼[Y|X]]. I am guessing that using this law we may be able to answer yes to the previous question as the set X is not fixed.



If my claim is not correct, please give a counterexample or prove why we cannot show $ mathbbE[X]neq mathbbE[Y]$







share|cite|improve this question













Suppose I have a distribution 𝔽 with mean M. Also, assume we have a set of i.i.d samples of size n denoted by X=$x_1,x_2,...,x_n$ from 𝔽. As a result, all $x_1,...,x_n$ are independent with identical distribution.



We know that 𝔼[X]=M.



Now suppose I derive another set of subsamples without replacement of size m from X where m ≤ n. Let's call this new subsamples Y=$y_1,y_2,...,y_m$.



Now can I say 𝔼[Y]=M?



Based on the rule of total expectation, we know that 𝔼[Y]=𝔼[𝔼[Y|X]]. I am guessing that using this law we may be able to answer yes to the previous question as the set X is not fixed.



If my claim is not correct, please give a counterexample or prove why we cannot show $ mathbbE[X]neq mathbbE[Y]$









share|cite|improve this question












share|cite|improve this question




share|cite|improve this question








edited Jul 30 at 14:40
























asked Jul 30 at 14:35









Infintyyy

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  • Please see this tutorial and reference on how to typeset math on this site.
    – joriki
    Jul 30 at 14:38










  • Thanks, is it possible for you to answer my question?
    – Infintyyy
    Jul 30 at 14:41
















  • Please see this tutorial and reference on how to typeset math on this site.
    – joriki
    Jul 30 at 14:38










  • Thanks, is it possible for you to answer my question?
    – Infintyyy
    Jul 30 at 14:41















Please see this tutorial and reference on how to typeset math on this site.
– joriki
Jul 30 at 14:38




Please see this tutorial and reference on how to typeset math on this site.
– joriki
Jul 30 at 14:38












Thanks, is it possible for you to answer my question?
– Infintyyy
Jul 30 at 14:41




Thanks, is it possible for you to answer my question?
– Infintyyy
Jul 30 at 14:41















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