Applied Mathematics 2014, 4(2): 47-55
DOI: 10.5923/j.am.20140402.02
Statistical Properties of the Exponentiated Generalized
Inverted Exponential Distribution
Oguntunde P. E.
1,*
, Adejumo A. O.
2
, Balogun O. S.
3
1
Department of Mathematics, Covenant University, Ota, Ogun State, Nigeria
2
Department of Statistics, University of Ilorin, Kwara State, Nigeria
3
Department of Statistics and Operations Research, Modibbo Adama University, Yola, Adamawa State, Nigeria
Abstract We provide another generalization of the inverted exponential distribution which serves as a competitive model
and an alternative to both the generalized inverse exponential distribution and the inverse exponential distribution. The model
is positively skewed and its shape could be decreasing or unimodal (depending on its parameter values). The statistical
properties of the proposed model are provided and the method of Maximum Likelihood Estimation (MLE) was proposed in
estimating its parameters.
Keywords Distributions, Estimation, Exponentiated, Generalization, Inverse Exponential, Positively Skewed
1. Introduction
The Exponentiated distributions have been studied widely
in statistics since 1995 and a number of authors have
developed various classes of these distributions; Lemonte et
al [1]. Mudholkar et al [2] introduced the Exponentiated
Weibull distribution and since then, a number of authors
have proposed and generalized many standard distributions
based on the Exponentiated distributions. The Exponentiated
Exponential distribution; Gupta and Kundu [3-5], The
Exponentiated Gamma, Exponentiated Weibull,
Exponentiated Gumbel and Exponentiated Frechet
distributions; Nadarajah and Kotz [6], The Exponentiated
Exponential-Geometric distribution; Silva et al [7], The
Exponentiated Generalized Inverse Gaussian distribution
Lemonte and Cordeiro [8], The Exponentiated
Kumaraswamy distribution; Lemonte et al [1], The
Exponentiated Inverted Weibull Distribution; Flaih et al [9]
and the Exponentiated Generalized Inverse Weibull; Elbatal
et al [10] distribution are examples of such in the literatures.
The Exponentiated distribution is derived by raising the
cumulative density function (cdf) of an arbitrary parent
distribution to an additional non-negative parameter, say
' ' γ . According to Lemonte et al [1], the parameter ' ' γ
characterizes the skewness, kurtosis and tails of the resulting
distribution.
Let X denote a random variable from an arbitrary parent
distribution G, the cumulative density function (cdf) of the
* Corresponding author:
peluemman@yahoo.com (Oguntunde P. E.)
Published online at http://journal.sapub.org/am
Copyright © 2014 Scientific & Academic Publishing. All Rights Reserved
resulting Exponentiated distribution is given by;
() () Fx Gx
γ
= ; 0 γ > (1)
where () Gx is the cdf of the parent distribution.
The corresponding probability density function (pdf) is
obtained by differentiating Equation (1) with respect to to
give;
1
() () () fx Gx gx
γ
γ
−
= (2)
Where
()
()
dG x
gx
dx
=
Once the cdf is obtained as in Equation (1), getting the pdf
is quite simple; it only involves the knowledge of
differentiation in calculus.
On the other hand, Cordeiro et al [11] proposed a new
class of distributions as an extension of the Exponentiated
type distribution which can be widely applied in many areas
of biology and engineering. Given a non-negative
continuous random variable X, the cdf of the Exponentiated
Generalized (EG) class of distribution is defined by;
{ } () 1 1 () Fx Gx
β
α
= − −
(3)
where , 0 αβ > are additional shape parameters.
It was noted in their research that the model in Equation (3)
has a tractability advantage over the Beta Generalized family
of distributions; Eugene et al [12] since Equation (3) does not
involve any special function like the incomplete beta
function. Equation (3) also has mild algebraic properties for
simulation purposes because its quantile function takes a