AN ANALYSIS OF THE SURVIVAL FUNCTION FOR XGD OF PATIENTS WITH COVID-19 USING BAYESIAN AND MAXIMUM LIKELIHOOD METHODS

This paper suggests a new probability distribution, called xgamma1 distribution. This distribution is generating as a mixture of exponential and gamma distributions which has one positive parameter (θ > 0). We studying and deriving the Mathematical, structural, and survival functions properties of the xgamma1 distribution and we use the Standard Bayesian and maximum likelihood estimation methods to estimate the new model parameter, and then it was compared the properties of Xgamma1 distribution with some other distributions such as the xgamma distribution and one parameter Lindley distribution. In addition we use the simulation for generating random samples and is found that the Standard Bayesian method is the best in estimating the survival function for the new distribution. Finally we found that Xgamma1 provides a better fit to data than xgamma and Lindley models when analyzing patients infected with the Covid-19 virus in AL-Najaf al-Ashraf, because achieved the lowest criterions (AIC, AICc, BIC) than other distributions.