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1 vote
1 answer
63 views

Find a two dimensional sufficient statistic for $\theta$

Let $\{X_i\}_{i=1}^n$ be conditional independent given $\theta$ with distribution $$p_{X_i | \theta} (x |\theta) = \frac{1}{2i\theta}, \ -i\theta<x<i\theta.$$ Find a two dimensional sufficient ...
Oskar's user avatar
  • 265
1 vote
2 answers
876 views

Show that the maximum of $x_1,...,x_n \sim \mathrm{Uniform}(0,\theta)$ is a sufficient statistic for $\theta$. (From definition)

Problem Show that the maximum of $x_1,...,x_n \sim \mathrm{Uniform}(0,\theta)$ is a sufficient statistic for $\theta$. Background This question has been asked before, but most answers tackle the ...
EssentialAnonymity's user avatar
4 votes
1 answer
365 views

minimal sufficient statistic for $U(\theta, \theta+c)$. $(\theta,c)$ unknown

Suppose $X_1,\cdots,X_n$ are $i.i.d$ from a distribution with p.d.f $$\delta_{(\theta,c)}(x)=\frac{1}{c}\mathbb{1}_{(x\in[\theta,\theta+c])},$$ where $\theta\in\mathbb{R}$ and $c\in\mathbb{R}^+$ ...
Tan's user avatar
  • 1,499
6 votes
1 answer
382 views

2-dimensional minimal sufficient statistic for $U(-k\theta+k,k\theta+k)$

Find a two dimensional minimal sufficient statistic for $\theta$ from $n$ independent random variables $X_k\sim > U(-k\theta+k,k\theta+k)$, $k\in\{1,\cdots,n\}$ Here is what I've attempted. The ...
Tan's user avatar
  • 1,499
3 votes
1 answer
8k views

Sufficient statistics in the uniform distribution case

I am currently studying sufficiency statistics. My notes say the following: A statistic $T(\mathbf{Y})$ is sufficient for $\theta$ if, and only if, for all $\theta \in \Theta$, $$L(\theta; \mathbf{y})...
The Pointer's user avatar
  • 2,096
2 votes
1 answer
368 views

How to find confidence interval for Uniform([a,1])?

Let $ U_1, \dots, U_n $ be a random sample of uniform distribution over $ [a,1] $. Construct a confidence interval for $ a $ with $ 1-\alpha = 0.95 $. I managed to show that $ T = \min\{U_i\} $ is ...
Krzysztof Antoniak's user avatar
1 vote
0 answers
48 views

What's wrong with this proof that the sample sum is sufficient for $\theta$ in $U(0,\theta)$?

So let's say $X_i ~ U(0, \theta)$, and let's consider the two-sample sample sum, $t = \bar{X_2} = (X_1 + X_2)/2$. So we want to show that $p(x|t) = p(x,t)/p(t) = p(x)/p(t)$ is independent of $\theta$....
user49404's user avatar
  • 457
1 vote
1 answer
1k views

Sufficient Statistic of Uniform $(-\theta,0)$

Let $X_1, ... , X_n$ be i.i.d random variables Uniform $(-\theta,0)$ , with $\theta > 0$ parameter \begin{align}f_{\theta}(x_1,x_2,\cdots,x_n)&=\prod_{i=1}^nf(x_i;\theta) \\&=\frac{1}{(\...
Pedros's user avatar
  • 213
3 votes
1 answer
2k views

Prove the maximum order statistic $X_{(n)}$ is a minimal sufficient statistic for the uniform$(0,\theta)$ family using a particular theorem

I'm doing Exercise 6.26 in Casella and Berger's Statistical Inference, and I'm trying to prove the following: "Use Theorem 6.6.5 to establish that, given a sample $X_1,...,X_n$, the maximum order ...
Ryker's user avatar
  • 211
3 votes
2 answers
1k views

Checking if a minimal sufficient statistic is complete

Let $X_1, \cdots, X_n$ be iid from a uniform distribution $U[-\theta, 2\theta]$ with $\theta \in \mathbb{R}^+$ unknown. Check if the minimal sufficient statistic of $\theta$ is complete. I found ...
Harry's user avatar
  • 1,387
2 votes
1 answer
3k views

Finding 2-dimensional sufficient statistic via Fisher-Neyman factorization when marginal pdf functions for x don't contain x

Let $X_1,...,X_n$ be mutually independent with pdfs given by $f_i(X_i\mid\theta) = 1/(2i\theta) $ where $ -i(\theta - 1)<x_i<i(\theta +1) $ and $\theta>0.$ To find a two-dimensional ...
David's user avatar
  • 1,276
6 votes
1 answer
8k views

Sufficient statistics for Uniform $(-\theta,\theta)$

So, I know that $\max(-X_{(1)},X_{(n)})$ is a sufficient statistic for the parameter $\theta$. But can I also say that $(X_{(1)},X_{(n)})$ are jointly sufficient for the parameter $\theta$ ? In other ...
Tricolor's user avatar
  • 307
2 votes
0 answers
143 views

Sufficiency and completeness of distribution

Let $X=(X_1,...,X_n)$ be drawn from the distribution with pmf $p(x_1,...,x_n)\propto \begin{cases} 1/ {\theta\choose n} & \text{if all } x_i \text{ are different and }1 \le\max(x)\le\theta \\ ...
ChuckP's user avatar
  • 903
4 votes
0 answers
563 views

The relationship between UMVUE and complete sufficient statistic [duplicate]

Let $X_1,...X_n$ $U(-\theta , \theta)$ I want to find the UMVUE of $\theta$ if it is exists. My answer is , there is no UMVUE in this case. Because there is no complete sufficient statistic that ...
student_R123's user avatar
6 votes
2 answers
2k views

Finding complete sufficient statistic

Let $X_1, \dots, X_n$ be iid. $\text{Uniform}[-\theta,\theta]$. I need to find the complete sufficient statistic for $\theta$ or prove there does not exist such. I know that $T = (X_{(1)}, X_{(n)} )$ ...
Sam88's user avatar
  • 348

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