Let X₁,..., Xn be a random sample of size n from the U(0, 0) distribution, where > 0 is an unknown parameter. Recall that the pdf fof the U(0, 0) distribution is of the form 0-¹ if 0

MATLAB: An Introduction with Applications
6th Edition
ISBN:9781119256830
Author:Amos Gilat
Publisher:Amos Gilat
Chapter1: Starting With Matlab
Section: Chapter Questions
Problem 1P
icon
Related questions
Question
**Random Sample and Estimator Concepts from Uniform Distribution**

Consider a random sample \(X_1, \cdots, X_n\) of size \(n\) from the \(U(0, \theta)\) distribution, where \(\theta > 0\) is an unknown parameter. The probability density function (pdf) of the \(U(0, \theta)\) distribution is given by:

\[
f(x) = 
\begin{cases} 
\theta^{-1} & \text{if } 0 < x < \theta \\
0 & \text{otherwise}
\end{cases}
\]

It is important to note that the information about \(\theta\) contained in the random sample \(X_1, \cdots, X_n\) equals the information about \(\theta\) contained in the statistic:

\[
T = \max(X_1, \cdots, X_n).
\]

**Understanding the Statistic \(T\):**

To understand why this is the case, consider obtaining the random sample in a sequential manner. You start with \(X_1\) and pause before obtaining \(X_2\). The value \(X_1\) gives you information that \(\theta > X_1\). Once you have \(X_1\), you receive \(X_2\). If \(X_2 > X_1\), then you gain further information about \(\theta\), specifically \(\theta > X_2\). If \(X_2 \leq X_1\), it doesn't add anything beyond confirming what you already know from \(X_1\). Therefore, the insight you gain continues to be that \(\theta\) exceeds the maximum of the observed values, which is \(T\).

**Tasks:**

(a) Demonstrate that \(T\) is the maximum likelihood estimator of \(\theta\). Recall that the likelihood function \(\mathcal{L}\) of \(\theta\), given a data sample \(x_1, \cdots, x_n\), is the product of \(f(x_1), \cdots, f(x_n)\).

(b) Develop an unbiased estimator of \(\theta\) that is not a function of \(T\) and compute its variance. Begin by calculating the expected value and the variance of the \(U(0, \theta)\) distribution.
Transcribed Image Text:**Random Sample and Estimator Concepts from Uniform Distribution** Consider a random sample \(X_1, \cdots, X_n\) of size \(n\) from the \(U(0, \theta)\) distribution, where \(\theta > 0\) is an unknown parameter. The probability density function (pdf) of the \(U(0, \theta)\) distribution is given by: \[ f(x) = \begin{cases} \theta^{-1} & \text{if } 0 < x < \theta \\ 0 & \text{otherwise} \end{cases} \] It is important to note that the information about \(\theta\) contained in the random sample \(X_1, \cdots, X_n\) equals the information about \(\theta\) contained in the statistic: \[ T = \max(X_1, \cdots, X_n). \] **Understanding the Statistic \(T\):** To understand why this is the case, consider obtaining the random sample in a sequential manner. You start with \(X_1\) and pause before obtaining \(X_2\). The value \(X_1\) gives you information that \(\theta > X_1\). Once you have \(X_1\), you receive \(X_2\). If \(X_2 > X_1\), then you gain further information about \(\theta\), specifically \(\theta > X_2\). If \(X_2 \leq X_1\), it doesn't add anything beyond confirming what you already know from \(X_1\). Therefore, the insight you gain continues to be that \(\theta\) exceeds the maximum of the observed values, which is \(T\). **Tasks:** (a) Demonstrate that \(T\) is the maximum likelihood estimator of \(\theta\). Recall that the likelihood function \(\mathcal{L}\) of \(\theta\), given a data sample \(x_1, \cdots, x_n\), is the product of \(f(x_1), \cdots, f(x_n)\). (b) Develop an unbiased estimator of \(\theta\) that is not a function of \(T\) and compute its variance. Begin by calculating the expected value and the variance of the \(U(0, \theta)\) distribution.
Expert Solution
steps

Step by step

Solved in 4 steps with 25 images

Blurred answer
Similar questions
Recommended textbooks for you
MATLAB: An Introduction with Applications
MATLAB: An Introduction with Applications
Statistics
ISBN:
9781119256830
Author:
Amos Gilat
Publisher:
John Wiley & Sons Inc
Probability and Statistics for Engineering and th…
Probability and Statistics for Engineering and th…
Statistics
ISBN:
9781305251809
Author:
Jay L. Devore
Publisher:
Cengage Learning
Statistics for The Behavioral Sciences (MindTap C…
Statistics for The Behavioral Sciences (MindTap C…
Statistics
ISBN:
9781305504912
Author:
Frederick J Gravetter, Larry B. Wallnau
Publisher:
Cengage Learning
Elementary Statistics: Picturing the World (7th E…
Elementary Statistics: Picturing the World (7th E…
Statistics
ISBN:
9780134683416
Author:
Ron Larson, Betsy Farber
Publisher:
PEARSON
The Basic Practice of Statistics
The Basic Practice of Statistics
Statistics
ISBN:
9781319042578
Author:
David S. Moore, William I. Notz, Michael A. Fligner
Publisher:
W. H. Freeman
Introduction to the Practice of Statistics
Introduction to the Practice of Statistics
Statistics
ISBN:
9781319013387
Author:
David S. Moore, George P. McCabe, Bruce A. Craig
Publisher:
W. H. Freeman