CALCULATING THE MEAN AND VARIANCE OF POWER SUMS WITH 2 LOG-NORMAL COMPONENTS

An efficient method for accurately calculating the mean and variance o f power sums with two log-normal components is presented. It involves numerical quadrature with integrands consisting of Gaussian probabilit y density function. Only the technique of transformation and the trape zoidal rule are used in the evaluation. The whole computational work a nd roundoff error are much lower than the one by Schwartz and Yeh. Bec ause of its high efficiency, no least-squares fit is necessary.