Abstract
Let are independent random variables from a distribution function , . We survey the likelihood ratio ordering of the convolution of the gamma random variables in terms of the majorization order of the two parameters holds. For , if and , we show that is larger than according to the likelihood ratio ordering. We find the useful bounds for the survival function and hazard rate function of convolution of non-identical gamma random variables.
Keywords: Convolution, likelihood ratio ordering, two-parameter majorization, gamma distribution, totally positivity.