Robust estimation of the mean











up vote
2
down vote

favorite












Problem:




Suppose we want to estimate the mean µ of a random variable $X$ from a
sample $X_1 , dots , X_N$ drawn independently from the distribution
of $X$. We want an $varepsilon$-accurate estimate, i.e. one that
falls in the interval $(mu − varepsilon, mu + varepsilon)$.



Show that a sample of size $N = O( log (delta^{−1} ), sigma^2 / varepsilon^2 )$ is sufficient to compute an $varepsilon$-accurate
estimate with probability at least $1 −delta$.



Hint: Use the median of $O(log(delta^{−1}))$ weak estimates.




It is easy to use Chebyshev's inequality to find a weak estimate of $N = O( sigma^2 / delta varepsilon^2 )$.



However, I do not how to find inequality about their median. The wikipedia of median (https://en.wikipedia.org/wiki/Median#The_sample_median) says sample median asymptotically normal but this does not give a bound for specific $N$. Any suggestion is welcome.










share|cite|improve this question


























    up vote
    2
    down vote

    favorite












    Problem:




    Suppose we want to estimate the mean µ of a random variable $X$ from a
    sample $X_1 , dots , X_N$ drawn independently from the distribution
    of $X$. We want an $varepsilon$-accurate estimate, i.e. one that
    falls in the interval $(mu − varepsilon, mu + varepsilon)$.



    Show that a sample of size $N = O( log (delta^{−1} ), sigma^2 / varepsilon^2 )$ is sufficient to compute an $varepsilon$-accurate
    estimate with probability at least $1 −delta$.



    Hint: Use the median of $O(log(delta^{−1}))$ weak estimates.




    It is easy to use Chebyshev's inequality to find a weak estimate of $N = O( sigma^2 / delta varepsilon^2 )$.



    However, I do not how to find inequality about their median. The wikipedia of median (https://en.wikipedia.org/wiki/Median#The_sample_median) says sample median asymptotically normal but this does not give a bound for specific $N$. Any suggestion is welcome.










    share|cite|improve this question
























      up vote
      2
      down vote

      favorite









      up vote
      2
      down vote

      favorite











      Problem:




      Suppose we want to estimate the mean µ of a random variable $X$ from a
      sample $X_1 , dots , X_N$ drawn independently from the distribution
      of $X$. We want an $varepsilon$-accurate estimate, i.e. one that
      falls in the interval $(mu − varepsilon, mu + varepsilon)$.



      Show that a sample of size $N = O( log (delta^{−1} ), sigma^2 / varepsilon^2 )$ is sufficient to compute an $varepsilon$-accurate
      estimate with probability at least $1 −delta$.



      Hint: Use the median of $O(log(delta^{−1}))$ weak estimates.




      It is easy to use Chebyshev's inequality to find a weak estimate of $N = O( sigma^2 / delta varepsilon^2 )$.



      However, I do not how to find inequality about their median. The wikipedia of median (https://en.wikipedia.org/wiki/Median#The_sample_median) says sample median asymptotically normal but this does not give a bound for specific $N$. Any suggestion is welcome.










      share|cite|improve this question













      Problem:




      Suppose we want to estimate the mean µ of a random variable $X$ from a
      sample $X_1 , dots , X_N$ drawn independently from the distribution
      of $X$. We want an $varepsilon$-accurate estimate, i.e. one that
      falls in the interval $(mu − varepsilon, mu + varepsilon)$.



      Show that a sample of size $N = O( log (delta^{−1} ), sigma^2 / varepsilon^2 )$ is sufficient to compute an $varepsilon$-accurate
      estimate with probability at least $1 −delta$.



      Hint: Use the median of $O(log(delta^{−1}))$ weak estimates.




      It is easy to use Chebyshev's inequality to find a weak estimate of $N = O( sigma^2 / delta varepsilon^2 )$.



      However, I do not how to find inequality about their median. The wikipedia of median (https://en.wikipedia.org/wiki/Median#The_sample_median) says sample median asymptotically normal but this does not give a bound for specific $N$. Any suggestion is welcome.







      probability median






      share|cite|improve this question













      share|cite|improve this question











      share|cite|improve this question




      share|cite|improve this question










      asked Nov 15 at 17:02









      Rikeijin

      878




      878



























          active

          oldest

          votes











          Your Answer





          StackExchange.ifUsing("editor", function () {
          return StackExchange.using("mathjaxEditing", function () {
          StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix) {
          StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["$", "$"], ["\\(","\\)"]]);
          });
          });
          }, "mathjax-editing");

          StackExchange.ready(function() {
          var channelOptions = {
          tags: "".split(" "),
          id: "69"
          };
          initTagRenderer("".split(" "), "".split(" "), channelOptions);

          StackExchange.using("externalEditor", function() {
          // Have to fire editor after snippets, if snippets enabled
          if (StackExchange.settings.snippets.snippetsEnabled) {
          StackExchange.using("snippets", function() {
          createEditor();
          });
          }
          else {
          createEditor();
          }
          });

          function createEditor() {
          StackExchange.prepareEditor({
          heartbeatType: 'answer',
          convertImagesToLinks: true,
          noModals: true,
          showLowRepImageUploadWarning: true,
          reputationToPostImages: 10,
          bindNavPrevention: true,
          postfix: "",
          imageUploader: {
          brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
          contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
          allowUrls: true
          },
          noCode: true, onDemand: true,
          discardSelector: ".discard-answer"
          ,immediatelyShowMarkdownHelp:true
          });


          }
          });














           

          draft saved


          draft discarded


















          StackExchange.ready(
          function () {
          StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f2999970%2frobust-estimation-of-the-mean%23new-answer', 'question_page');
          }
          );

          Post as a guest















          Required, but never shown






























          active

          oldest

          votes













          active

          oldest

          votes









          active

          oldest

          votes






          active

          oldest

          votes
















           

          draft saved


          draft discarded



















































           


          draft saved


          draft discarded














          StackExchange.ready(
          function () {
          StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f2999970%2frobust-estimation-of-the-mean%23new-answer', 'question_page');
          }
          );

          Post as a guest















          Required, but never shown





















































          Required, but never shown














          Required, but never shown












          Required, but never shown







          Required, but never shown

































          Required, but never shown














          Required, but never shown












          Required, but never shown







          Required, but never shown







          Popular posts from this blog

          How do I know what Microsoft account the skydrive app is syncing to?

          Grease: Live!

          When does type information flow backwards in C++?