/*! 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} Q9E Question: Suppose that \({{\bf{X... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

Question: Suppose that \({{\bf{X}}_{\bf{1}}}{\bf{,}}...{\bf{,}}{{\bf{X}}_{\bf{n}}}\) form a random sample from a distribution for which the p.d.f. f (x|θ ) is as follows:

\(\begin{array}{c}{\bf{f}}\left( {{\bf{x|\theta }}} \right){\bf{ = \theta }}{{\bf{x}}^{{\bf{\theta - 1}}\,\,\,}}{\bf{,0 < \theta < 1}}\\{\bf{ = 0}}\,\,\,\,{\bf{otherwise}}\end{array}\)

Also, suppose that the value of θ is unknown (θ > 0). Find the M.L.E. of θ

Short Answer

Expert verified

\(\frac{{ - n}}{{\sum\limits_{i = 1}^n {\log {x_i}} }}\)

Step by step solution

01

Given information

\({X_1},...,{X_n}\)form a random sample and the pdf is

\(\begin{array}{c}f\left( {x|\theta } \right) = \theta {x^{\theta - 1\,\,\,}},0 < \theta < 1\\ = 0\,\,\,\,{\rm{otherwise}}\end{array}\)

We need to calculate the M.L.E. of θ

02

Step-2: Calculation of the M.L.E. of θ

Since \(0 < \theta < 1\) the likelihood function is as follows

\(f\left( {x|\theta } \right) = {\theta ^n}{\left( {\prod\limits_{i = 1}^n {{x_i}} } \right)^{\theta - 1}}\)

Taking logarithm and differentiating with respect to \(\theta \) we get

\(\frac{{\partial L\left( \theta \right)}}{{\partial \theta }} = \frac{n}{\theta } + \sum\limits_{i = 1}^n {\log {x_i}} \)

Now for maximum value we have \(\frac{{\partial L\left( \theta \right)}}{{\partial \theta }} = 0\)

\( \Rightarrow \hat \theta = \frac{{ - n}}{{\sum\limits_{i = 1}^n {\log {x_i}} }}\)

Hence the M.L.E. is \(\hat \theta = \frac{{ - n}}{{\sum\limits_{i = 1}^n {\log {x_i}} }}\)

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

Suppose that a random sample \({{\bf{X}}_{\bf{1}}}{\bf{,}}...{\bf{,}}{{\bf{X}}_{\bf{n}}}\) is drawn from the Pareto distribution with parameters \({{\bf{x}}_{\bf{0}}}\,\,\,\,{\bf{and}}\,\,\,{\bf{\alpha }}\).

a. If \({{\bf{x}}_{\bf{0}}}\) is known and \({\bf{\alpha > 0}}\) unknown, find a sufficient statistic

b. If \({\bf{\alpha }}\) is known and \({{\bf{x}}_{\bf{0}}}\) unknown, find a sufficient statistic.

Question: Consider again the conditions in Exercise 2, but suppose also that it is known that\(\)\(\frac{{\bf{1}}}{{\bf{2}}} \le {\bf{p}} \le \frac{{\bf{2}}}{{\bf{3}}}\). If the observations in the random sample of 70 purchases are as given in Exercise 2, what is the M.L.E. of p?

Question: Let \({{\bf{x}}_{\bf{1}}}{\bf{,}}...{\bf{,}}{{\bf{x}}_{\bf{n}}}\) be distinct numbers. Let Y be a discrete random variable with the following p.f.:

\(\begin{array}{c}{\bf{f}}\left( {\bf{y}} \right){\bf{ = }}\frac{{\bf{1}}}{{\bf{n}}}\,{\bf{if}}\,{\bf{y}} \in \left\{ {{{\bf{x}}_{\bf{1}}}{\bf{,}}...{\bf{,}}{{\bf{x}}_{\bf{n}}}} \right\}\\ = 0\,otherwise\end{array}\)

Prove that Var(Y ) is given by Eq. (7.5.5).

Question: Suppose that \({{\bf{X}}_{\bf{1}}}{\bf{,}}...{\bf{,}}{{\bf{X}}_{\bf{n}}}\)form a random sample from an exponential distribution for which the value of the parameter β is unknown (β > 0). Find the M.L.E. of β.

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 that the prior distribution of θ is the gamma distribution with parameters α = 3 and β = 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. Determine the posterior distribution of θ.

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.