Mathematical Statistics question

In summary, the conversation discusses whether 2X-bar, a sample mean of a random variable with uniform p.d.f, is an unbiased and consistent estimator for theta. The solution involves showing that the expectation of the estimator is equal to theta and demonstrating consistency by showing that the variance of the estimate converges to zero. The use of the normal distribution is not necessary.
  • #1
peace-Econ
34
0

Homework Statement



let X be a random variable with uniform p.d.f over the interval (0, theta)

Determine whether 2X-bar (sample mean) is an unbiased and consistent estimator for theta


Homework Equations



bx(theta)=EX-theta

The Attempt at a Solution



By using normal distribution, how does it look like...? I'm stuck with this question. Hope someone can help.
 
Physics news on Phys.org
  • #2
Why would you use the normal distribution? You need to show two things.

First, that the expectation of your statistic is [tex] \theta [/tex] - you can write the estimator as a linear combination of the [tex] X_i [/tex] in the sample, so use properties of expectation.

Second, consistency. Review the definition: you need to show the estimator converges in probability to [tex] \theta [/tex]. Can you show that the variance of the estimate converges to zero?
 
  • #3
thank you for your reply. please forget about normal distribution, my mistake.

So sorry, could you show that...?
 
  • #4
No. You need to try some work yourself, and show it here, before any more hints.
 
  • #5
Got it. Let me try it.
 

1. What is the difference between descriptive and inferential statistics?

Descriptive statistics involve summarizing and describing a set of data, while inferential statistics involve making predictions or inferences about a larger population based on a sample of data.

2. What is the Central Limit Theorem and how does it relate to statistical analysis?

The Central Limit Theorem states that as the sample size increases, the distribution of sample means will approach a normal distribution, regardless of the population's underlying distribution. This allows for the use of statistical methods that assume a normal distribution, even if the data is not normally distributed.

3. What is the difference between a parameter and a statistic?

A parameter is a numerical value that describes a population, while a statistic is a numerical value that describes a sample from that population. Parameters are often unknown and estimated using statistics.

4. What is the purpose of hypothesis testing in statistics?

Hypothesis testing is used to determine whether a certain assumption or claim about a population is supported by the data. It involves comparing a sample statistic to a hypothesized value and determining the likelihood of obtaining that result if the null hypothesis (no difference or no effect) is true.

5. How is regression analysis used in statistics?

Regression analysis is a statistical method used to identify and quantify the relationship between one or more predictor variables and a response variable. It can be used for prediction, understanding the relationship between variables, and identifying influential factors.

Similar threads

  • Calculus and Beyond Homework Help
Replies
1
Views
566
  • Calculus and Beyond Homework Help
Replies
4
Views
1K
  • Set Theory, Logic, Probability, Statistics
Replies
6
Views
1K
  • Set Theory, Logic, Probability, Statistics
Replies
7
Views
441
  • Calculus and Beyond Homework Help
Replies
11
Views
2K
Replies
14
Views
1K
  • Set Theory, Logic, Probability, Statistics
Replies
13
Views
2K
  • Calculus and Beyond Homework Help
Replies
2
Views
2K
  • Calculus and Beyond Homework Help
Replies
5
Views
2K
Replies
1
Views
1K
Back
Top