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2 votes
1 answer
86 views

Sufficient Statistic for a family of distributions consisting of Poisson family and Bernoulli family

Suppose $(X_1, . . . ,X_n)$ is an i.i.d. sample from the distribution $f_{\theta,k}(x)$, where $\theta \in (0, 1)$ and $k = 1, 2$. Assume that $$f_{\theta, k}(x)=\begin{cases} \text{Poisson($\theta)$},...
user671269's user avatar
1 vote
0 answers
37 views

Sufficient Statistic for a finite family of Normal distributions

Suppose we have a finite family of normal distributions $P=\{N(0, 1), N(0, 2), N(1, 2), N(2, 2)\}$ and we want to find a sufficient statistic for this family. Intuitively it is clear that as the means ...
user671269's user avatar
5 votes
1 answer
188 views

A lemma concerning the distribution of sufficient statistic from exponential family

I understand Lemma 8 in Chapter 1 from Lehmann's Testing Statistical Hypotheses [or Lemma 2.7.2 in Lehmann and Romano] as follows: If the pdf of an exponential family is $$p_{\theta}(x)=\exp\bigg\{\...
rryan's user avatar
  • 65
4 votes
3 answers
824 views

How to prove any one-to-one function of minimal sufficient statistic is minimal sufficient?

So I want to prove that any one-to-one function of minimal sufficient statistic is also minimal sufficient. Here is my proof: Let $T$ be a minimal sufficient statistic and $f$ is a one-to-one function ...
Alex He's user avatar
  • 181
0 votes
1 answer
151 views

Understanding the Importance of "Sufficiency" within Statistics

I am trying to better understand what it means to be a "sufficient statistic". "In statistics, a statistic is sufficient with respect to a statistical model and its associated unknown ...
stats_noob's user avatar
0 votes
1 answer
76 views

Sufficient Statistic for Absolutely Continuous Distribution [duplicate]

The following is a homework problem. Please tell me if my solution is correct and if not please point out my mistakes. Let $x_{1}, x_{2},...,x_{M}$ be i.i.d. samples from the absolute continuous ...
Jason Butler's user avatar
0 votes
0 answers
167 views

Sufficient statistic for a given distribution from exponential form

Given a particular form, i can verify whether it is sufficient statistic or not using $\frac{p_\theta(x_1,x_2...x_n)}{p_\theta(T(x_1,x_2...x_n))}$ is independendent of $\theta$ then i can say $T(\bar ...
Nascimento de Cos's user avatar
1 vote
0 answers
2k views

Sufficient Statistic for Variance (Normal Distribution)

Suppose $X_1, \dots, X_n \sim N(\mu, \sigma^2)$. If $\mu$ is known and $\sigma^2$ is unknown, prove that $S^2$ is a sufficient statistics for $\sigma^2$. Likelihood: $$ L = (2\pi\sigma^2)^{-n/2} \cdot ...
James Hampshire 's user avatar
0 votes
1 answer
41 views

replication of minimal sufficient statistic

Suppose we have a minimal sufficient statistic for observations $X_1, ...,X_n$ that are i.i.d from distribution $f(X|\theta)$, namely $T(X) = (T_1,...,T_k)$ which is a $k$ dimensional statistics. Now ...
mohammad's user avatar
  • 135
0 votes
1 answer
503 views

Finding the conditional distribution of single sample point given sample mean for $N(\mu, 1)$

Suppose that $X_1, \ldots, X_n$ are iid from $N(\mu, 1)$. Find the conditional distribution of $X_1$ given $\bar{X}_n = \frac{1}{n}\sum^n_{i=1} X_i$. So I know that $\bar{X}_n$ is a sufficient ...
zerxee's user avatar
  • 51
1 vote
0 answers
65 views

Minimal sufficient statistics

Suppose we have data $X = X_1,\ldots,X_n$, $Y = Y_1,\ldots,Y_n$ that is i.i.d. generated by a distribution $\mathbb{P}_\theta$. Let $T$ be a test statistic such that that $T(X) = T(Y)$ if and only ...
User197307's user avatar
1 vote
1 answer
222 views

Gaussian sufficient statistic calculation

Consider the Gaussian model $$ Y_i = \beta + \epsilon_i,\, i = 1, \cdots, n,\; \mbox{where}\; \epsilon_i \stackrel{i.i.d.}{\sim} \mathcal{N}(0, \sigma^2), $$ parametrized by $\beta$, with known $\...
Michael's user avatar
  • 3,348
3 votes
1 answer
209 views

Proving completeness of highest-order statistic using Leibnitz' Rule

Suppose that $X_1,...,X_n$ are iid with common pdf given by $$f(x;\theta)=2e^{2x}\theta^{-2}I( x<log(\theta)).$$ I am tasked with finding a complete-sufficient statistic for $\theta$, and I have ...
David's user avatar
  • 1,276
3 votes
2 answers
128 views

Minimal sufficient statistics of increasing dimensionality (not equal to the number of observations)

Restricting the attention to the case of fixed parameters support, it's my understanding that (minimal) sufficient statistics of fixed dimensionality, i.e. a fixed number of of them, exists in, and ...
KRao's user avatar
  • 31
4 votes
1 answer
83 views

When family of DF's $\mathcal{P}$ fail to be dominated by a measure $\mu$

On the topic of minimal sufficient statistics, there is an important theorem which requires the family of probability distributions $\mathcal{P}$ is dominated by some measure $\mu$. As I understand it,...
Xiaomi's user avatar
  • 2,564

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