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2 votes
0 answers
46 views

No Existence of Efficient estimator

I need to prove that given $(X_1,...,X_n)$ from the density $$\frac{1}{\theta}x^{\frac{1}{\theta}-1}1_{(0,1)}$$ no efficient estimator exists for $g(\theta)$=$\frac{1}{{\theta}+1}$. I have shown that ...
Onofrio Olivieri's user avatar
1 vote
1 answer
54 views

What is the distribution of the unbiased estimator of variance for normally distributed variables?

I must be making some mistake in my derivation of the distribution of the unbiased variance estimator for i.i.d. $X_{i} \sim \mathcal{N}\left(\mu, \sigma^{2}\right)$. We have $\bar{X} =\frac{1}{n}\sum\...
YEp d's user avatar
  • 11
1 vote
0 answers
120 views

Distribution of $F_n^{-1}(3/4)-F_n^{-1}(1/4)$ [closed]

Given $X_1,X_2,...X_n\overset{\text{iid}}{\sim}F$, find the distribution of the sample inter quartile range, $F_n^{-1}(3/4)-F_n^{-1}(1/4)$ in terms of $F$ where, $F_n$ is the emperical distribution ...
reyna's user avatar
  • 385
2 votes
1 answer
167 views

I need to prove that $\hat\theta=\max\{X_1,...,X_n\}$ is a mean square consistent estimator for $\theta$

Let $X_1,...,X_n$ a i.i.d from a population with distribution $U[0,\theta]$, i.e., $f_{X_i}(x)=\frac{1}{\theta}g_{[0,\theta]}(x)$, for $i=1, \ldots, n$ where \begin{align} g_{[0,\theta]}(x) = \begin{...
Willow Douglas's user avatar
1 vote
1 answer
59 views

How to find asymptotically normal estimator if I know probability density function [closed]

I have $X_1, X_2,\ldots,X_n$ be a random sample of size n from a distribution with probability density function: $$p(x) = \theta^2xe^{-\theta x}I (x > 0).$$ How can I find an asymptotically normal ...
Karlos Margaritos's user avatar
1 vote
0 answers
42 views

Show that $T=\sum_{i=1}^n X_i$ is a sufficient statistic for $p$ [duplicate]

I try to use the definition of sufficient statistic to prove that Suppose that $X_1,\dots, X_n$ is an iid random sample from $X\sim \mathrm{Bernoulli}(p)$. Show that $T=\sum_{i=1}^n X_i$ is a ...
Hermi's user avatar
  • 747
0 votes
1 answer
50 views

Minimizing variance of sequence of independent but not identically distributed random variable

I tried to work on the problem Let $(X_n)$ be a sequence of independent random variables with $E[X_n]=\mu$ and $Var[X_n]=n$ for every $n \in \mathbb{N}$. Find the statistic of the form $\sum_{i=1}^...
Alex He's user avatar
  • 181
0 votes
0 answers
85 views

Estimator for the propensity for consumption c = C/Y

I've an exercise where it asks to propose an estimator for the propensity for consumption: $c = C/Y$ where $C$ is the consume and $Y$ is the income. Since the consumption function $C = c_0 + c_1 Y$ is ...
iStats7238's user avatar
9 votes
1 answer
421 views

Minimax estimator for geometric distribution

I'm trying to solve this problem: Let $X$ be a single sample from Geo($p$) where $p ∈ (0, 1)$. Find a minimax estimator for $p$ under the loss $L(p, δ(x)) = (p−δ(x))^2/ p(1−p)$ . I'm trying to put ...
user115608's user avatar
3 votes
1 answer
88 views

Consistency of a simple estimator for $y_i = \beta_1 x_i + u_i$

Let $y_i = \beta_1 x_i + u_i$ for $i=1,2,..,n$. If I define $$\hat \beta_1 = \frac{y_1 + y_n}{x_1 + x_n}$$ then whether my $\hat \beta_1$ will be consistent or not in this setup? For my estimator to ...
Ujjwal's user avatar
  • 43
0 votes
0 answers
123 views

Unbiased estimators for uniform distribution

I have a given question that I just cannot figure out. From what I can understand, both estimators would be unbiased (since e_1 is the sample mean and e_2 is an unbiased estimator for uniform ...
Lucinda Hills's user avatar
5 votes
2 answers
350 views

What is Bayes estimator of $\theta$ when loss function is $L(\theta,a)=I(|\theta -a|>\delta)$?

Suppose $X$ given $\theta$ has pdf $f(x\mid \theta)=e^{-(x-\theta)}I(x>\theta)$ and there is a standard Cauchy prior on $\theta$. As part of an exercise, I am trying to find a Bayes estimator of $\...
StubbornAtom's user avatar
  • 11.5k
1 vote
0 answers
42 views

On the naming of two different median estimators

Assume that $X \sim \mathcal{E}(\lambda)$ is, for example, exponential with $\lambda > 0$. Given a data sample $X_1, \ldots, X_n$, assume that I want to estimate the median of $X$. Consider these ...
runr's user avatar
  • 642
1 vote
1 answer
77 views

consistency of maximum likelihood estimator

For population with n size and following density function $$f(y, a)= (1/6a^4)y^3e^{-y/a}$$ For that, I have found the maximum likelihood estimator of a which is $\hat{a}= \bar{y}/4$ I have also shon ...
1190's user avatar
  • 1,140
0 votes
0 answers
31 views

Antithetic variate as control variate to find optimal constant [duplicate]

Problem: If $\hat{θ}_1$ and $\hat{θ}_2$ are unbiased estimators of $θ$, and $\hat{θ}_1$ and $\hat{θ}_2$ are antithetic, we derived that $c^∗ = 1/2$ is the optimal constant that minimizes the variance ...
ForestGump's user avatar

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