Simple confidence intervals for lognormal means and their differences with environmental applications

Abstract The lognormal distribution has frequently been applied to approximate environmental data, with inference focusing on arithmetic means. Confidence interval estimation involving lognormal means in small to moderate sample sizes has received much attention over the years without a simple procedure in sight. We therefore propose a closed‐form procedure for constructing confidence intervals for a lognormal mean and a difference between two lognormal means. The advantage of our procedure is that it only requires confidence limits for a normal mean and variance. The results of a numerical study show that our method performs as well as the generalized confidence interval (GCI) approach, which relies completely on computer simulation. Two real datasets are used to illustrate the methodology. Copyright © 2008 John Wiley & Sons, Ltd.