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A MIXTURE OF EXPONENTIAL AND IFR GAMMA DISTRIBUTIONS HAVING AN UPSIDEDOWN BATHTUB-SHAPED FAILURE RATE

Published online by Cambridge University Press:  30 July 2012

Henry W. Block
Affiliation:
University of Pittsburgh, PA E-mail: hwb@stat.pitt.edu
Naftali A. Langberg
Affiliation:
University of Haifa, Israel E-mail: naftalilan@gmail.com
Thomas H. Savits
Affiliation:
University of Pittsburgh, PA E-mail: tsavits@stat.pitt.edu

Abstract

We consider a mixture of one exponential distribution and one gamma distribution with increasing failure rate. For the right choice of parameters, it is shown that its failure rate has an upsidedown bathtub shape failure rate. We also consider a mixture of a family of exponentials and a family of gamma distributions and obtain a similar result.

Type
Research Article
Copyright
Copyright © Cambridge University Press 2012

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