Relation betweeen expected area of square and rectangle

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Hello I am struggling with the following question, can anybody help please?




Consider a positive real valued random variable $X$

Experiment A: Draw a sample of $X$ and create a square with it as the edge length, and call this square $S$.

Experiment B: Draw two independent samples of $X$ and create a rectangle with these two as sides, and call this rectangle $R$. Let
$$A = E[textArea(S)] (E - textExpectation)$$
and
$$B = E[textArea(R)]$$
What is relation between $A$ and $B$?

Edit: I have no idea how to approach this kind of questions any help is highly appreciated.











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  • Welcome to MSE. It will be more likely that you will get an answer if you show us that you made an effort. This should be added to the question rather than in the comments.
    – José Carlos Santos
    Sep 6 at 7:52






  • 1




    As mentioned above, at least you should try to express those area in terms of $X, X_1, X_2$ etc.
    – BGM
    Sep 6 at 8:01










  • Hi! What do you mean by $E-Expectation?$
    – Riccardo Ceccon
    Sep 6 at 8:12










  • Hmm I found this question interesting it seems that the expected area of the square could be way bigger than the expected area of the rectangle if the variance of $X$ is super big...
    – HJ_beginner
    Sep 6 at 8:26







  • 1




    @RiccardoCeccon I just meant that E(x) means Expectation of x
    – Anurag Shah
    Sep 6 at 8:47














up vote
0
down vote

favorite












Hello I am struggling with the following question, can anybody help please?




Consider a positive real valued random variable $X$

Experiment A: Draw a sample of $X$ and create a square with it as the edge length, and call this square $S$.

Experiment B: Draw two independent samples of $X$ and create a rectangle with these two as sides, and call this rectangle $R$. Let
$$A = E[textArea(S)] (E - textExpectation)$$
and
$$B = E[textArea(R)]$$
What is relation between $A$ and $B$?

Edit: I have no idea how to approach this kind of questions any help is highly appreciated.











share|cite|improve this question























  • Welcome to MSE. It will be more likely that you will get an answer if you show us that you made an effort. This should be added to the question rather than in the comments.
    – José Carlos Santos
    Sep 6 at 7:52






  • 1




    As mentioned above, at least you should try to express those area in terms of $X, X_1, X_2$ etc.
    – BGM
    Sep 6 at 8:01










  • Hi! What do you mean by $E-Expectation?$
    – Riccardo Ceccon
    Sep 6 at 8:12










  • Hmm I found this question interesting it seems that the expected area of the square could be way bigger than the expected area of the rectangle if the variance of $X$ is super big...
    – HJ_beginner
    Sep 6 at 8:26







  • 1




    @RiccardoCeccon I just meant that E(x) means Expectation of x
    – Anurag Shah
    Sep 6 at 8:47












up vote
0
down vote

favorite









up vote
0
down vote

favorite











Hello I am struggling with the following question, can anybody help please?




Consider a positive real valued random variable $X$

Experiment A: Draw a sample of $X$ and create a square with it as the edge length, and call this square $S$.

Experiment B: Draw two independent samples of $X$ and create a rectangle with these two as sides, and call this rectangle $R$. Let
$$A = E[textArea(S)] (E - textExpectation)$$
and
$$B = E[textArea(R)]$$
What is relation between $A$ and $B$?

Edit: I have no idea how to approach this kind of questions any help is highly appreciated.











share|cite|improve this question















Hello I am struggling with the following question, can anybody help please?




Consider a positive real valued random variable $X$

Experiment A: Draw a sample of $X$ and create a square with it as the edge length, and call this square $S$.

Experiment B: Draw two independent samples of $X$ and create a rectangle with these two as sides, and call this rectangle $R$. Let
$$A = E[textArea(S)] (E - textExpectation)$$
and
$$B = E[textArea(R)]$$
What is relation between $A$ and $B$?

Edit: I have no idea how to approach this kind of questions any help is highly appreciated.








probability expected-value






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edited Sep 6 at 9:22









Riccardo Ceccon

877320




877320










asked Sep 6 at 7:45









Anurag Shah

32




32











  • Welcome to MSE. It will be more likely that you will get an answer if you show us that you made an effort. This should be added to the question rather than in the comments.
    – José Carlos Santos
    Sep 6 at 7:52






  • 1




    As mentioned above, at least you should try to express those area in terms of $X, X_1, X_2$ etc.
    – BGM
    Sep 6 at 8:01










  • Hi! What do you mean by $E-Expectation?$
    – Riccardo Ceccon
    Sep 6 at 8:12










  • Hmm I found this question interesting it seems that the expected area of the square could be way bigger than the expected area of the rectangle if the variance of $X$ is super big...
    – HJ_beginner
    Sep 6 at 8:26







  • 1




    @RiccardoCeccon I just meant that E(x) means Expectation of x
    – Anurag Shah
    Sep 6 at 8:47
















  • Welcome to MSE. It will be more likely that you will get an answer if you show us that you made an effort. This should be added to the question rather than in the comments.
    – José Carlos Santos
    Sep 6 at 7:52






  • 1




    As mentioned above, at least you should try to express those area in terms of $X, X_1, X_2$ etc.
    – BGM
    Sep 6 at 8:01










  • Hi! What do you mean by $E-Expectation?$
    – Riccardo Ceccon
    Sep 6 at 8:12










  • Hmm I found this question interesting it seems that the expected area of the square could be way bigger than the expected area of the rectangle if the variance of $X$ is super big...
    – HJ_beginner
    Sep 6 at 8:26







  • 1




    @RiccardoCeccon I just meant that E(x) means Expectation of x
    – Anurag Shah
    Sep 6 at 8:47















Welcome to MSE. It will be more likely that you will get an answer if you show us that you made an effort. This should be added to the question rather than in the comments.
– José Carlos Santos
Sep 6 at 7:52




Welcome to MSE. It will be more likely that you will get an answer if you show us that you made an effort. This should be added to the question rather than in the comments.
– José Carlos Santos
Sep 6 at 7:52




1




1




As mentioned above, at least you should try to express those area in terms of $X, X_1, X_2$ etc.
– BGM
Sep 6 at 8:01




As mentioned above, at least you should try to express those area in terms of $X, X_1, X_2$ etc.
– BGM
Sep 6 at 8:01












Hi! What do you mean by $E-Expectation?$
– Riccardo Ceccon
Sep 6 at 8:12




Hi! What do you mean by $E-Expectation?$
– Riccardo Ceccon
Sep 6 at 8:12












Hmm I found this question interesting it seems that the expected area of the square could be way bigger than the expected area of the rectangle if the variance of $X$ is super big...
– HJ_beginner
Sep 6 at 8:26





Hmm I found this question interesting it seems that the expected area of the square could be way bigger than the expected area of the rectangle if the variance of $X$ is super big...
– HJ_beginner
Sep 6 at 8:26





1




1




@RiccardoCeccon I just meant that E(x) means Expectation of x
– Anurag Shah
Sep 6 at 8:47




@RiccardoCeccon I just meant that E(x) means Expectation of x
– Anurag Shah
Sep 6 at 8:47










1 Answer
1






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votes

















up vote
1
down vote



accepted










Hint: $A=E(X_1^2)$ and $B=E(X_1X_2)=E(X_1)E(X_2)=E^2(X_1)$






share|cite|improve this answer




















  • Ok so as E(X^2) >= E(X)^2 we can conclude A >= B. Correct me if I'm wrong.
    – Anurag Shah
    Sep 6 at 8:46






  • 1




    And the difference $A-B$ is actually the variance of $X$. Did you notice?
    – Yuta
    Sep 6 at 9:25










  • yeah from that observation I remembered this result of inequality!
    – Anurag Shah
    Sep 6 at 9:33










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1 Answer
1






active

oldest

votes








1 Answer
1






active

oldest

votes









active

oldest

votes






active

oldest

votes








up vote
1
down vote



accepted










Hint: $A=E(X_1^2)$ and $B=E(X_1X_2)=E(X_1)E(X_2)=E^2(X_1)$






share|cite|improve this answer




















  • Ok so as E(X^2) >= E(X)^2 we can conclude A >= B. Correct me if I'm wrong.
    – Anurag Shah
    Sep 6 at 8:46






  • 1




    And the difference $A-B$ is actually the variance of $X$. Did you notice?
    – Yuta
    Sep 6 at 9:25










  • yeah from that observation I remembered this result of inequality!
    – Anurag Shah
    Sep 6 at 9:33














up vote
1
down vote



accepted










Hint: $A=E(X_1^2)$ and $B=E(X_1X_2)=E(X_1)E(X_2)=E^2(X_1)$






share|cite|improve this answer




















  • Ok so as E(X^2) >= E(X)^2 we can conclude A >= B. Correct me if I'm wrong.
    – Anurag Shah
    Sep 6 at 8:46






  • 1




    And the difference $A-B$ is actually the variance of $X$. Did you notice?
    – Yuta
    Sep 6 at 9:25










  • yeah from that observation I remembered this result of inequality!
    – Anurag Shah
    Sep 6 at 9:33












up vote
1
down vote



accepted







up vote
1
down vote



accepted






Hint: $A=E(X_1^2)$ and $B=E(X_1X_2)=E(X_1)E(X_2)=E^2(X_1)$






share|cite|improve this answer












Hint: $A=E(X_1^2)$ and $B=E(X_1X_2)=E(X_1)E(X_2)=E^2(X_1)$







share|cite|improve this answer












share|cite|improve this answer



share|cite|improve this answer










answered Sep 6 at 8:30









Yuta

62929




62929











  • Ok so as E(X^2) >= E(X)^2 we can conclude A >= B. Correct me if I'm wrong.
    – Anurag Shah
    Sep 6 at 8:46






  • 1




    And the difference $A-B$ is actually the variance of $X$. Did you notice?
    – Yuta
    Sep 6 at 9:25










  • yeah from that observation I remembered this result of inequality!
    – Anurag Shah
    Sep 6 at 9:33
















  • Ok so as E(X^2) >= E(X)^2 we can conclude A >= B. Correct me if I'm wrong.
    – Anurag Shah
    Sep 6 at 8:46






  • 1




    And the difference $A-B$ is actually the variance of $X$. Did you notice?
    – Yuta
    Sep 6 at 9:25










  • yeah from that observation I remembered this result of inequality!
    – Anurag Shah
    Sep 6 at 9:33















Ok so as E(X^2) >= E(X)^2 we can conclude A >= B. Correct me if I'm wrong.
– Anurag Shah
Sep 6 at 8:46




Ok so as E(X^2) >= E(X)^2 we can conclude A >= B. Correct me if I'm wrong.
– Anurag Shah
Sep 6 at 8:46




1




1




And the difference $A-B$ is actually the variance of $X$. Did you notice?
– Yuta
Sep 6 at 9:25




And the difference $A-B$ is actually the variance of $X$. Did you notice?
– Yuta
Sep 6 at 9:25












yeah from that observation I remembered this result of inequality!
– Anurag Shah
Sep 6 at 9:33




yeah from that observation I remembered this result of inequality!
– Anurag Shah
Sep 6 at 9:33

















 

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