A Generalized Suja Distribution with Application to Lifetime Data
Samuel U. Enogwe *
Department of Statistics, Michael Okpara University of Agriculture, Umudike, Nigeria.
Christiana O. Atuejide
Department of Statistics, Michael Okpara University of Agriculture, Umudike, Nigeria.
Chinonye E. Oguba
Department of Mathematics and Statistics, Imo State Polytechnic Omuma, Nigeria.
Paul C. Ugwuoke
Department of Statistics, Michael Okpara University of Agriculture, Umudike, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
This paper introduces a generalized Suja distribution called the Kumaraswamy-Suja (KW-Suja) distribution using the Kumaraswamy generator. The proposed distribution has Suja distribution as a special case. Some statistical and reliability properties of the new distribution were derived and the method of maximum likelihood was employed for estimating the model parameters. The usefulness and flexibility of the KW-Suja distribution were illustrated with a real lifetime data. Results based on the log-likelihood and goodness of fit statistics values showed that the KW-Suja distribution provides a better fit to the data than the other competing distributions considered in this study. The KW-Suja distribution is therefore recommended for effective modelling of the unimodal or bimodal continuous lifetime data with non-decreasing shape and bathtub-shaped failure rate.
Keywords: Bimodal data, hazard rate function, maximum likelihood method, Kumaraswamy generator, Suja distribution