Central Limit Theorem - Different Forms
up vote
1
down vote
favorite
Given the following function:
$W_n = frac{1}{sqrt{n}}Pi_{k=1}^{infty}log(U_k)$ where $U_k$ is uniformly distributed from $1$ to $e$.
Does ${W_n}_{ngeq 1}$ converge in distribution?
I found that: $log(Pi_{k=1}^{infty}U_k)$ is equivalent to $sum_{k=1}^infty log(U_k)$ which can be called $S_n$.
$W_n$ can then be written as $frac{S_n}{sqrt{n}}$. The answers says that this function has the distribution $mathcal{N}(sqrt{n}E[log(U_k)],V[log(U_k])$ where $V$ is variance. The final result is that it does not converge because its mean is dependent on $n$.
I am having trouble understanding where the multiplication by $sqrt{n}$ comes from.
I know that $frac{S_n-nmu}{sqrt{nsigma^2}}$ has the distribution $mathcal{N}(0,1)$ by the central limit theorem. I also saw in my book that $frac{S_n-nmu}{sqrt{n}}$ has the distribution $mathcal{N}(0,sigma^2)$.
I am just having trouble understanding how modifying that equation has the corresponding effect on the distribution.
probability-theory convergence summation weak-convergence central-limit-theorem
add a comment |
up vote
1
down vote
favorite
Given the following function:
$W_n = frac{1}{sqrt{n}}Pi_{k=1}^{infty}log(U_k)$ where $U_k$ is uniformly distributed from $1$ to $e$.
Does ${W_n}_{ngeq 1}$ converge in distribution?
I found that: $log(Pi_{k=1}^{infty}U_k)$ is equivalent to $sum_{k=1}^infty log(U_k)$ which can be called $S_n$.
$W_n$ can then be written as $frac{S_n}{sqrt{n}}$. The answers says that this function has the distribution $mathcal{N}(sqrt{n}E[log(U_k)],V[log(U_k])$ where $V$ is variance. The final result is that it does not converge because its mean is dependent on $n$.
I am having trouble understanding where the multiplication by $sqrt{n}$ comes from.
I know that $frac{S_n-nmu}{sqrt{nsigma^2}}$ has the distribution $mathcal{N}(0,1)$ by the central limit theorem. I also saw in my book that $frac{S_n-nmu}{sqrt{n}}$ has the distribution $mathcal{N}(0,sigma^2)$.
I am just having trouble understanding how modifying that equation has the corresponding effect on the distribution.
probability-theory convergence summation weak-convergence central-limit-theorem
Just checking, the product in outside of logarithm?
– Siong Thye Goh
Nov 28 at 16:46
No sorry, Ill edit the question.
– jackana3
Nov 28 at 16:56
add a comment |
up vote
1
down vote
favorite
up vote
1
down vote
favorite
Given the following function:
$W_n = frac{1}{sqrt{n}}Pi_{k=1}^{infty}log(U_k)$ where $U_k$ is uniformly distributed from $1$ to $e$.
Does ${W_n}_{ngeq 1}$ converge in distribution?
I found that: $log(Pi_{k=1}^{infty}U_k)$ is equivalent to $sum_{k=1}^infty log(U_k)$ which can be called $S_n$.
$W_n$ can then be written as $frac{S_n}{sqrt{n}}$. The answers says that this function has the distribution $mathcal{N}(sqrt{n}E[log(U_k)],V[log(U_k])$ where $V$ is variance. The final result is that it does not converge because its mean is dependent on $n$.
I am having trouble understanding where the multiplication by $sqrt{n}$ comes from.
I know that $frac{S_n-nmu}{sqrt{nsigma^2}}$ has the distribution $mathcal{N}(0,1)$ by the central limit theorem. I also saw in my book that $frac{S_n-nmu}{sqrt{n}}$ has the distribution $mathcal{N}(0,sigma^2)$.
I am just having trouble understanding how modifying that equation has the corresponding effect on the distribution.
probability-theory convergence summation weak-convergence central-limit-theorem
Given the following function:
$W_n = frac{1}{sqrt{n}}Pi_{k=1}^{infty}log(U_k)$ where $U_k$ is uniformly distributed from $1$ to $e$.
Does ${W_n}_{ngeq 1}$ converge in distribution?
I found that: $log(Pi_{k=1}^{infty}U_k)$ is equivalent to $sum_{k=1}^infty log(U_k)$ which can be called $S_n$.
$W_n$ can then be written as $frac{S_n}{sqrt{n}}$. The answers says that this function has the distribution $mathcal{N}(sqrt{n}E[log(U_k)],V[log(U_k])$ where $V$ is variance. The final result is that it does not converge because its mean is dependent on $n$.
I am having trouble understanding where the multiplication by $sqrt{n}$ comes from.
I know that $frac{S_n-nmu}{sqrt{nsigma^2}}$ has the distribution $mathcal{N}(0,1)$ by the central limit theorem. I also saw in my book that $frac{S_n-nmu}{sqrt{n}}$ has the distribution $mathcal{N}(0,sigma^2)$.
I am just having trouble understanding how modifying that equation has the corresponding effect on the distribution.
probability-theory convergence summation weak-convergence central-limit-theorem
probability-theory convergence summation weak-convergence central-limit-theorem
edited Dec 1 at 11:01
Davide Giraudo
124k16150259
124k16150259
asked Nov 28 at 16:20
jackana3
153
153
Just checking, the product in outside of logarithm?
– Siong Thye Goh
Nov 28 at 16:46
No sorry, Ill edit the question.
– jackana3
Nov 28 at 16:56
add a comment |
Just checking, the product in outside of logarithm?
– Siong Thye Goh
Nov 28 at 16:46
No sorry, Ill edit the question.
– jackana3
Nov 28 at 16:56
Just checking, the product in outside of logarithm?
– Siong Thye Goh
Nov 28 at 16:46
Just checking, the product in outside of logarithm?
– Siong Thye Goh
Nov 28 at 16:46
No sorry, Ill edit the question.
– jackana3
Nov 28 at 16:56
No sorry, Ill edit the question.
– jackana3
Nov 28 at 16:56
add a comment |
1 Answer
1
active
oldest
votes
up vote
0
down vote
accepted
I believe by $S_n$, you intend to mean $S_n = sum_{k=1}^n log(U_k).$
begin{align}
Eleft[ frac{S_n}{sqrt{n}}right] &= frac1{sqrt{n}}Eleft[sum_{k=1}^n log(U_k) right] \
&= frac1{sqrt{n}}left(n E(log(U_1 right)))\
&= sqrt{n} E(log(U_1))
end{align}
begin{align}
Vleft[ frac{S_n}{sqrt{n}}right] &= frac1{n}Vleft[sum_{k=1}^n log(U_k) right] \
&= frac1{n}left(n V(log(U_1 right)))\
&= V(log(U_1))
end{align}
Ok I see it now. It was really very simple, thank you Siong
– jackana3
Nov 28 at 17:08
add a comment |
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
});
}
});
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3017335%2fcentral-limit-theorem-different-forms%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
0
down vote
accepted
I believe by $S_n$, you intend to mean $S_n = sum_{k=1}^n log(U_k).$
begin{align}
Eleft[ frac{S_n}{sqrt{n}}right] &= frac1{sqrt{n}}Eleft[sum_{k=1}^n log(U_k) right] \
&= frac1{sqrt{n}}left(n E(log(U_1 right)))\
&= sqrt{n} E(log(U_1))
end{align}
begin{align}
Vleft[ frac{S_n}{sqrt{n}}right] &= frac1{n}Vleft[sum_{k=1}^n log(U_k) right] \
&= frac1{n}left(n V(log(U_1 right)))\
&= V(log(U_1))
end{align}
Ok I see it now. It was really very simple, thank you Siong
– jackana3
Nov 28 at 17:08
add a comment |
up vote
0
down vote
accepted
I believe by $S_n$, you intend to mean $S_n = sum_{k=1}^n log(U_k).$
begin{align}
Eleft[ frac{S_n}{sqrt{n}}right] &= frac1{sqrt{n}}Eleft[sum_{k=1}^n log(U_k) right] \
&= frac1{sqrt{n}}left(n E(log(U_1 right)))\
&= sqrt{n} E(log(U_1))
end{align}
begin{align}
Vleft[ frac{S_n}{sqrt{n}}right] &= frac1{n}Vleft[sum_{k=1}^n log(U_k) right] \
&= frac1{n}left(n V(log(U_1 right)))\
&= V(log(U_1))
end{align}
Ok I see it now. It was really very simple, thank you Siong
– jackana3
Nov 28 at 17:08
add a comment |
up vote
0
down vote
accepted
up vote
0
down vote
accepted
I believe by $S_n$, you intend to mean $S_n = sum_{k=1}^n log(U_k).$
begin{align}
Eleft[ frac{S_n}{sqrt{n}}right] &= frac1{sqrt{n}}Eleft[sum_{k=1}^n log(U_k) right] \
&= frac1{sqrt{n}}left(n E(log(U_1 right)))\
&= sqrt{n} E(log(U_1))
end{align}
begin{align}
Vleft[ frac{S_n}{sqrt{n}}right] &= frac1{n}Vleft[sum_{k=1}^n log(U_k) right] \
&= frac1{n}left(n V(log(U_1 right)))\
&= V(log(U_1))
end{align}
I believe by $S_n$, you intend to mean $S_n = sum_{k=1}^n log(U_k).$
begin{align}
Eleft[ frac{S_n}{sqrt{n}}right] &= frac1{sqrt{n}}Eleft[sum_{k=1}^n log(U_k) right] \
&= frac1{sqrt{n}}left(n E(log(U_1 right)))\
&= sqrt{n} E(log(U_1))
end{align}
begin{align}
Vleft[ frac{S_n}{sqrt{n}}right] &= frac1{n}Vleft[sum_{k=1}^n log(U_k) right] \
&= frac1{n}left(n V(log(U_1 right)))\
&= V(log(U_1))
end{align}
edited Nov 29 at 3:08
answered Nov 28 at 17:03
Siong Thye Goh
98k1463116
98k1463116
Ok I see it now. It was really very simple, thank you Siong
– jackana3
Nov 28 at 17:08
add a comment |
Ok I see it now. It was really very simple, thank you Siong
– jackana3
Nov 28 at 17:08
Ok I see it now. It was really very simple, thank you Siong
– jackana3
Nov 28 at 17:08
Ok I see it now. It was really very simple, thank you Siong
– jackana3
Nov 28 at 17:08
add a comment |
Thanks for contributing an answer to Mathematics Stack Exchange!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
Use MathJax to format equations. MathJax reference.
To learn more, see our tips on writing great answers.
Some of your past answers have not been well-received, and you're in danger of being blocked from answering.
Please pay close attention to the following guidance:
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3017335%2fcentral-limit-theorem-different-forms%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
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
Just checking, the product in outside of logarithm?
– Siong Thye Goh
Nov 28 at 16:46
No sorry, Ill edit the question.
– jackana3
Nov 28 at 16:56