Distribution of sufficient statistic of negative bionomial distribution












1














Negative binomial distribution with known parameter k has the following distribution:
$$
f(r;k,p)=binom{k+r-1}{k}(1-p)^{r}p^k~~~~~text{for}~r=0,1,2,ldots
$$

Then the join probability of $n$ Negative binomial independent variables, has distribution:
$$
f(textbf{r};k,p)=prod_{i=1}^nbinom{k+ r_i -1}{k}(1-p)^{sum_{i=1}^{n} r_i}p^{nk}
$$

Then it can be rewritten in exponential form as:
$$
begin{align}
f(k;r,p) &=prod_{i=1}^nbinom{k+r_i-1}{k}expleft[ln(p^{kn}(1-p)^{^{sum_{i=1}^{n} r_i}})right] \
&=prod_{i=1}^nbinom{k+r_i-1}{k}expleft[{ln(1-p)sum_{i=1}^{n} r_i} + knln(p)right] \
end{align}
$$

From above we can see that the sufficient statistic for $p$ is $$T(textbf{r}) = sum_{i=1}^{n} r_i $$



My question is what is the distribution of $r_i$










share|cite|improve this question






















  • Try to generalise the answers here. Also see math.stackexchange.com/questions/2189105/….
    – StubbornAtom
    Nov 30 at 14:14


















1














Negative binomial distribution with known parameter k has the following distribution:
$$
f(r;k,p)=binom{k+r-1}{k}(1-p)^{r}p^k~~~~~text{for}~r=0,1,2,ldots
$$

Then the join probability of $n$ Negative binomial independent variables, has distribution:
$$
f(textbf{r};k,p)=prod_{i=1}^nbinom{k+ r_i -1}{k}(1-p)^{sum_{i=1}^{n} r_i}p^{nk}
$$

Then it can be rewritten in exponential form as:
$$
begin{align}
f(k;r,p) &=prod_{i=1}^nbinom{k+r_i-1}{k}expleft[ln(p^{kn}(1-p)^{^{sum_{i=1}^{n} r_i}})right] \
&=prod_{i=1}^nbinom{k+r_i-1}{k}expleft[{ln(1-p)sum_{i=1}^{n} r_i} + knln(p)right] \
end{align}
$$

From above we can see that the sufficient statistic for $p$ is $$T(textbf{r}) = sum_{i=1}^{n} r_i $$



My question is what is the distribution of $r_i$










share|cite|improve this question






















  • Try to generalise the answers here. Also see math.stackexchange.com/questions/2189105/….
    – StubbornAtom
    Nov 30 at 14:14
















1












1








1







Negative binomial distribution with known parameter k has the following distribution:
$$
f(r;k,p)=binom{k+r-1}{k}(1-p)^{r}p^k~~~~~text{for}~r=0,1,2,ldots
$$

Then the join probability of $n$ Negative binomial independent variables, has distribution:
$$
f(textbf{r};k,p)=prod_{i=1}^nbinom{k+ r_i -1}{k}(1-p)^{sum_{i=1}^{n} r_i}p^{nk}
$$

Then it can be rewritten in exponential form as:
$$
begin{align}
f(k;r,p) &=prod_{i=1}^nbinom{k+r_i-1}{k}expleft[ln(p^{kn}(1-p)^{^{sum_{i=1}^{n} r_i}})right] \
&=prod_{i=1}^nbinom{k+r_i-1}{k}expleft[{ln(1-p)sum_{i=1}^{n} r_i} + knln(p)right] \
end{align}
$$

From above we can see that the sufficient statistic for $p$ is $$T(textbf{r}) = sum_{i=1}^{n} r_i $$



My question is what is the distribution of $r_i$










share|cite|improve this question













Negative binomial distribution with known parameter k has the following distribution:
$$
f(r;k,p)=binom{k+r-1}{k}(1-p)^{r}p^k~~~~~text{for}~r=0,1,2,ldots
$$

Then the join probability of $n$ Negative binomial independent variables, has distribution:
$$
f(textbf{r};k,p)=prod_{i=1}^nbinom{k+ r_i -1}{k}(1-p)^{sum_{i=1}^{n} r_i}p^{nk}
$$

Then it can be rewritten in exponential form as:
$$
begin{align}
f(k;r,p) &=prod_{i=1}^nbinom{k+r_i-1}{k}expleft[ln(p^{kn}(1-p)^{^{sum_{i=1}^{n} r_i}})right] \
&=prod_{i=1}^nbinom{k+r_i-1}{k}expleft[{ln(1-p)sum_{i=1}^{n} r_i} + knln(p)right] \
end{align}
$$

From above we can see that the sufficient statistic for $p$ is $$T(textbf{r}) = sum_{i=1}^{n} r_i $$



My question is what is the distribution of $r_i$







probability statistics






share|cite|improve this question













share|cite|improve this question











share|cite|improve this question




share|cite|improve this question










asked Nov 28 at 14:09









Wywana

535




535












  • Try to generalise the answers here. Also see math.stackexchange.com/questions/2189105/….
    – StubbornAtom
    Nov 30 at 14:14




















  • Try to generalise the answers here. Also see math.stackexchange.com/questions/2189105/….
    – StubbornAtom
    Nov 30 at 14:14


















Try to generalise the answers here. Also see math.stackexchange.com/questions/2189105/….
– StubbornAtom
Nov 30 at 14:14






Try to generalise the answers here. Also see math.stackexchange.com/questions/2189105/….
– StubbornAtom
Nov 30 at 14:14

















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',
autoActivateHeartbeat: false,
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%2f3017187%2fdistribution-of-sufficient-statistic-of-negative-bionomial-distribution%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




















































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.




draft saved


draft discarded














StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3017187%2fdistribution-of-sufficient-statistic-of-negative-bionomial-distribution%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

Wiesbaden

Marschland

Dieringhausen