For what value of $c$, we have $bar{theta}$ is unbiased?












0












$begingroup$



Given a population with the density function
$$f(x)=frac{2(theta-x)}{theta^2}$$ for $0<x<theta$, consider the estimator of $theta$ of the form $bar{theta}=cbar{x}$ where $c$ is constant.
For what value of $c$, do we have that $bar{theta}$ is unbiased?




My attempt:



By definition, a estimator is unbiased if $E[bar{theta}]=theta$



But here i'm a little confused because i have a density function. Can someone help me?










share|cite|improve this question











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    0












    $begingroup$



    Given a population with the density function
    $$f(x)=frac{2(theta-x)}{theta^2}$$ for $0<x<theta$, consider the estimator of $theta$ of the form $bar{theta}=cbar{x}$ where $c$ is constant.
    For what value of $c$, do we have that $bar{theta}$ is unbiased?




    My attempt:



    By definition, a estimator is unbiased if $E[bar{theta}]=theta$



    But here i'm a little confused because i have a density function. Can someone help me?










    share|cite|improve this question











    $endgroup$















      0












      0








      0





      $begingroup$



      Given a population with the density function
      $$f(x)=frac{2(theta-x)}{theta^2}$$ for $0<x<theta$, consider the estimator of $theta$ of the form $bar{theta}=cbar{x}$ where $c$ is constant.
      For what value of $c$, do we have that $bar{theta}$ is unbiased?




      My attempt:



      By definition, a estimator is unbiased if $E[bar{theta}]=theta$



      But here i'm a little confused because i have a density function. Can someone help me?










      share|cite|improve this question











      $endgroup$





      Given a population with the density function
      $$f(x)=frac{2(theta-x)}{theta^2}$$ for $0<x<theta$, consider the estimator of $theta$ of the form $bar{theta}=cbar{x}$ where $c$ is constant.
      For what value of $c$, do we have that $bar{theta}$ is unbiased?




      My attempt:



      By definition, a estimator is unbiased if $E[bar{theta}]=theta$



      But here i'm a little confused because i have a density function. Can someone help me?







      probability






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      share|cite|improve this question













      share|cite|improve this question




      share|cite|improve this question








      edited Nov 25 '18 at 21:56









      Clement C.

      49.8k33886




      49.8k33886










      asked Nov 25 '18 at 21:43









      Bvss12Bvss12

      1,790618




      1,790618






















          1 Answer
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          $begingroup$

          This may get you started:
          $$E[bartheta]=E[cbar X]=cE[bar X]=frac{c}{n}sum_{i=1}^nE[X_i]$$
          Then using the density function, you can find the expected value inside the sum.






          share|cite|improve this answer









          $endgroup$









          • 1




            $begingroup$
            Thanks for all!
            $endgroup$
            – Bvss12
            Nov 25 '18 at 22:17











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          1 Answer
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          active

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          1 Answer
          1






          active

          oldest

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          active

          oldest

          votes






          active

          oldest

          votes









          1












          $begingroup$

          This may get you started:
          $$E[bartheta]=E[cbar X]=cE[bar X]=frac{c}{n}sum_{i=1}^nE[X_i]$$
          Then using the density function, you can find the expected value inside the sum.






          share|cite|improve this answer









          $endgroup$









          • 1




            $begingroup$
            Thanks for all!
            $endgroup$
            – Bvss12
            Nov 25 '18 at 22:17
















          1












          $begingroup$

          This may get you started:
          $$E[bartheta]=E[cbar X]=cE[bar X]=frac{c}{n}sum_{i=1}^nE[X_i]$$
          Then using the density function, you can find the expected value inside the sum.






          share|cite|improve this answer









          $endgroup$









          • 1




            $begingroup$
            Thanks for all!
            $endgroup$
            – Bvss12
            Nov 25 '18 at 22:17














          1












          1








          1





          $begingroup$

          This may get you started:
          $$E[bartheta]=E[cbar X]=cE[bar X]=frac{c}{n}sum_{i=1}^nE[X_i]$$
          Then using the density function, you can find the expected value inside the sum.






          share|cite|improve this answer









          $endgroup$



          This may get you started:
          $$E[bartheta]=E[cbar X]=cE[bar X]=frac{c}{n}sum_{i=1}^nE[X_i]$$
          Then using the density function, you can find the expected value inside the sum.







          share|cite|improve this answer












          share|cite|improve this answer



          share|cite|improve this answer










          answered Nov 25 '18 at 21:50









          gd1035gd1035

          4571210




          4571210








          • 1




            $begingroup$
            Thanks for all!
            $endgroup$
            – Bvss12
            Nov 25 '18 at 22:17














          • 1




            $begingroup$
            Thanks for all!
            $endgroup$
            – Bvss12
            Nov 25 '18 at 22:17








          1




          1




          $begingroup$
          Thanks for all!
          $endgroup$
          – Bvss12
          Nov 25 '18 at 22:17




          $begingroup$
          Thanks for all!
          $endgroup$
          – Bvss12
          Nov 25 '18 at 22:17


















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