/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Q2E Question: Suppose that the propo... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

Question: Suppose that the proportion θ of defective items in a large shipment is unknown, and the prior distribution of θ is the beta distribution for which the parameters are \(\alpha = 5\) and\(\beta = 10\) . Suppose also that 20 items are selected randomly from the shipment and that exactly one of these items is found to be defective. If the squared error loss function is used, what is the Bayes estimate of θ?

Short Answer

Expert verified

The Bayes estimate of \(\theta \) based on the squared error loss function is\(\frac{6}{{35}}\) .

Step by step solution

01

Given information

It is given that the proportion \(\theta \)of defective items in a large shipment is unknown and a prior distribution of\(\theta \) is equal to the beta distribution with parameters \(\alpha = 5\) and\(\beta = 10\)

Also, it is given that 20 items are selected randomly from the shipment and each one is found to be defective. That is, n=20 and\(x = 1\) .

02

Computing the Bayes estimates of \(\theta \)based on squared error loss functions

Here,

\(n = 20\) and \(x = 1\)

Also,

The prior distribution of \(\theta \) is the Beta distribution with parameters \(\alpha = 5\) and\(\beta = 10\)

Since the Bayes estimate of\(\theta \)for the squared loss function is given by,

\(\widehat \theta = \frac{{\alpha + x}}{{\alpha + \beta + n}}\)

Therefore,

\(\begin{array}{c}\widehat \theta = \frac{{5 + 1}}{{5 + 10 + 20}}\\ = \frac{6}{{35}}\\ = 0.1714\end{array}\)

Therefore, the Bayes estimate of \(\theta \)based on the squared error loss function is\(\frac{6}{{35}}\) .

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

Question: Consider the conditions of Exercise 2 again. Suppose that the prior distribution of θ is as given in Exercise 2, and suppose again that 20 items are selected at random from the shipment.

a. For what number of defective items in the sample will the mean squared error of the Bayes estimate be a maximum?

b. For what number the mean squared error of the Bayes estimate will be a minimum?

Suppose that a random sample of size n is taken from a Poisson distribution for which the value of the mean θ is unknown, and the prior distribution of θ is a gamma distribution for which the mean is\({\mu _0}\). Show that the mean of the posterior distribution of θ will be a weighted average having the form\({\gamma _n}{\overline X _n} + \left( {1 - {\gamma _n}} \right){\mu _0}\)and show that \({\gamma _n} \to 1\) as\(n \to \infty \).

Suppose that the number of defects in a 1200-foot roll of magnetic recording tape has a Poisson distribution for which the value of the mean θ is unknown, and the prior distribution of θ is the gamma distribution with parameters \(\alpha = 3\) and \(\beta = 1\). When five rolls of this tape are selected at random and inspected, the numbers of defects found on the rolls are 2, 2, 6, 0, and 3. If the squared error loss function is used, what is the Bayes estimate of θ?

Suppose that a random sample of size n is taken from the Bernoulli distribution with parameter θ, which is unknown, and that the prior distribution of θ is a beta distribution for which the mean is\({\mu _0}\). Show that the mean of the posterior distribution of θ will be a weighted average having the form \({\gamma _n}{\overline X _n} + \left( {1 - {\gamma _n}} \right){\mu _0}\)and show that \({\gamma _n} \to 1\)as\(n \to \infty \).

Let θ be a parameter with parameter space \({\bf{\Omega }}\) equal to an interval of real numbers (possibly unbounded). Let X have p.d.f. or p.f. \({\bf{f}}\left( {{\bf{x;\theta }}} \right)\) conditional on θ. Let T = r(X) be a statistic. Assume that T is sufficient. Prove that, for every possible prior p.d.f. for θ, the posterior p.d.f. of θ given X = x depends on x only through r(x).

See all solutions

Recommended explanations on Math Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.