Sum of the $N-K$ largest out of $N$ normal random variables with different variables











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Given $N$ independent normal random variables, $X_1,X_2,ldots,X_N$, the ordered sequence is denoted as $X_{(1)}, X_{(2)}, ldots,X_{(N)}$ where $X_{(1)}ge X_{(2)}ge cdotsge X_{(N)}$.



Let $X_isim N(mu_i,sigma^2_i)$, if $sigma_i=sigma_j$ for all $ineq j$, then we can have the exact distribution of $sum_{i=1}^{N-K}X_{(i)}$ as mentioned in following paper "On the exact distribution of the sum of the largest n − k out of n normal random variables with differing mean values".



I would like to know if there is any result for identical means and different variances, i.e., Suppose $mu_i=mu_j$ for all $ineq j$ and $sigma_1gesigma_2gecdotsgesigma_N$, what is the distribution of $sum_{i=1}^{N-K}X_{(i)}$?










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    Given $N$ independent normal random variables, $X_1,X_2,ldots,X_N$, the ordered sequence is denoted as $X_{(1)}, X_{(2)}, ldots,X_{(N)}$ where $X_{(1)}ge X_{(2)}ge cdotsge X_{(N)}$.



    Let $X_isim N(mu_i,sigma^2_i)$, if $sigma_i=sigma_j$ for all $ineq j$, then we can have the exact distribution of $sum_{i=1}^{N-K}X_{(i)}$ as mentioned in following paper "On the exact distribution of the sum of the largest n − k out of n normal random variables with differing mean values".



    I would like to know if there is any result for identical means and different variances, i.e., Suppose $mu_i=mu_j$ for all $ineq j$ and $sigma_1gesigma_2gecdotsgesigma_N$, what is the distribution of $sum_{i=1}^{N-K}X_{(i)}$?










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      up vote
      0
      down vote

      favorite









      up vote
      0
      down vote

      favorite











      Given $N$ independent normal random variables, $X_1,X_2,ldots,X_N$, the ordered sequence is denoted as $X_{(1)}, X_{(2)}, ldots,X_{(N)}$ where $X_{(1)}ge X_{(2)}ge cdotsge X_{(N)}$.



      Let $X_isim N(mu_i,sigma^2_i)$, if $sigma_i=sigma_j$ for all $ineq j$, then we can have the exact distribution of $sum_{i=1}^{N-K}X_{(i)}$ as mentioned in following paper "On the exact distribution of the sum of the largest n − k out of n normal random variables with differing mean values".



      I would like to know if there is any result for identical means and different variances, i.e., Suppose $mu_i=mu_j$ for all $ineq j$ and $sigma_1gesigma_2gecdotsgesigma_N$, what is the distribution of $sum_{i=1}^{N-K}X_{(i)}$?










      share|cite|improve this question













      Given $N$ independent normal random variables, $X_1,X_2,ldots,X_N$, the ordered sequence is denoted as $X_{(1)}, X_{(2)}, ldots,X_{(N)}$ where $X_{(1)}ge X_{(2)}ge cdotsge X_{(N)}$.



      Let $X_isim N(mu_i,sigma^2_i)$, if $sigma_i=sigma_j$ for all $ineq j$, then we can have the exact distribution of $sum_{i=1}^{N-K}X_{(i)}$ as mentioned in following paper "On the exact distribution of the sum of the largest n − k out of n normal random variables with differing mean values".



      I would like to know if there is any result for identical means and different variances, i.e., Suppose $mu_i=mu_j$ for all $ineq j$ and $sigma_1gesigma_2gecdotsgesigma_N$, what is the distribution of $sum_{i=1}^{N-K}X_{(i)}$?







      probability probability-distributions






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      asked Nov 21 at 5:38









      Wu Ting-Yi

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