Sum of percentiles compared to percentile of the sum












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Consider random variables X_ij, where i is in {1,...,T} and j is in {1,...,M}. Can we compare these two statements?



Sum{over j}(95th percentile {over i} of X_ij) and
95th percentile {over i}(Sum{over j} of X_ij)



I personally conjecture that 95th percentile of the sum of random variables is less than sum of 95th percentile of the random variables. I am not sure how to go about rigorously proving it though.










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    – Confounded
    Jan 26 '17 at 19:10
















0












$begingroup$


Consider random variables X_ij, where i is in {1,...,T} and j is in {1,...,M}. Can we compare these two statements?



Sum{over j}(95th percentile {over i} of X_ij) and
95th percentile {over i}(Sum{over j} of X_ij)



I personally conjecture that 95th percentile of the sum of random variables is less than sum of 95th percentile of the random variables. I am not sure how to go about rigorously proving it though.










share|cite|improve this question









$endgroup$












  • $begingroup$
    Did you find an answer to your question?
    $endgroup$
    – Confounded
    Jan 26 '17 at 19:10














0












0








0





$begingroup$


Consider random variables X_ij, where i is in {1,...,T} and j is in {1,...,M}. Can we compare these two statements?



Sum{over j}(95th percentile {over i} of X_ij) and
95th percentile {over i}(Sum{over j} of X_ij)



I personally conjecture that 95th percentile of the sum of random variables is less than sum of 95th percentile of the random variables. I am not sure how to go about rigorously proving it though.










share|cite|improve this question









$endgroup$




Consider random variables X_ij, where i is in {1,...,T} and j is in {1,...,M}. Can we compare these two statements?



Sum{over j}(95th percentile {over i} of X_ij) and
95th percentile {over i}(Sum{over j} of X_ij)



I personally conjecture that 95th percentile of the sum of random variables is less than sum of 95th percentile of the random variables. I am not sure how to go about rigorously proving it though.







percentile






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asked Apr 10 '15 at 17:13









ShNShN

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  • $begingroup$
    Did you find an answer to your question?
    $endgroup$
    – Confounded
    Jan 26 '17 at 19:10


















  • $begingroup$
    Did you find an answer to your question?
    $endgroup$
    – Confounded
    Jan 26 '17 at 19:10
















$begingroup$
Did you find an answer to your question?
$endgroup$
– Confounded
Jan 26 '17 at 19:10




$begingroup$
Did you find an answer to your question?
$endgroup$
– Confounded
Jan 26 '17 at 19:10










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If all your random variables have the same distribution and are perfectly correlated (i.e. they always take the same random value) then the percentile of the sum will be exactly the same as the sum of percentiles.






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    0












    $begingroup$

    If all your random variables have the same distribution and are perfectly correlated (i.e. they always take the same random value) then the percentile of the sum will be exactly the same as the sum of percentiles.






    share|cite|improve this answer









    $endgroup$


















      0












      $begingroup$

      If all your random variables have the same distribution and are perfectly correlated (i.e. they always take the same random value) then the percentile of the sum will be exactly the same as the sum of percentiles.






      share|cite|improve this answer









      $endgroup$
















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        0








        0





        $begingroup$

        If all your random variables have the same distribution and are perfectly correlated (i.e. they always take the same random value) then the percentile of the sum will be exactly the same as the sum of percentiles.






        share|cite|improve this answer









        $endgroup$



        If all your random variables have the same distribution and are perfectly correlated (i.e. they always take the same random value) then the percentile of the sum will be exactly the same as the sum of percentiles.







        share|cite|improve this answer












        share|cite|improve this answer



        share|cite|improve this answer










        answered Apr 10 '15 at 17:25









        user2566092user2566092

        21.5k1947




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