30
Scientific Journal of Pure and Applied Sciences (2012) 1(1) 30-39
Bayesian analysis of exponentiated gamma distribution under type II censored
samples
N. Feroze
a,
*, M. Aslam
b
a
Department of Mathematics and Statistics, AIOU, Islamabad, Pakistan.
b
Department of and Statistics, Quaid-i-Azam University, Islamabad, Pakistan.
*
Corresponding author: Department of Mathematics and Statistics, AIOU, Islamabad, Pakistan.
A R T I C L E I N F O
Article history:
Received 28 September 2012
Accepted 08 October 2012
Available online 30 October 2012
Keywords:
Posterior distributions
Loss functions
Bayes estimators
Posterior risks
A B S T R A C T
The paper is concerned with posterior analysis of exponentiated
gamma distribution for type II censored samples. The expressions for
Bayes estimators and associated risks have been derived under
different priors. The entropy and quadratic loss functions have been
assumed for estimation. The posterior predictive distributions have
been obtained and corresponding intervals have been constructed.
The study aims to find out a suitable estimator of the parameter of
the distribution. The findings of the study suggest that the
performance of estimators under gamma prior using entropy loss
function is the best.
© 2012 Sjournals. All rights reserved.
1. Introduction
The exponential distribution has been widely used in time to failure data analysis and is preferred for
situations where hazard rate is constant. In case of monotonic hazard rate, a number of distributions have been
suggested but Weibull and gamma distributions are mostly used. The gamma distribution has a major constraint
that its distribution function and survival function cannot be expressed in nice closed forms which create
difficulties for further mathematical manipulations. The distribution function, the survival function or the hazard
function for the distribution are often evaluated numerically. This is one of the vital reasons that made the gamma
distribution unpopular in comparison to the Weibull distribution. Although Weibull distribution has a nice closed
form for hazard and survival function, but it has its own disadvantages. For example, Bain and Engelhardt (1991)
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Original article