Tables for Comparing Two Normal Variances or Two Gamma Means

Abstract

Tables for constructing the uniformly most accurate unbiased confidence interval of level 1 − α for σ 1 2 /σ 2 2 , where σ 1 2 and σ 2 2 are the variances of two normal distributions, and for tests of level α of hypotheses specifying the value of σ 1 2 /σ 2 2 are given for α = .1, .05, .01, .001, n 1 , n 2 = 1(1)20(2)30, 36, 45, 60, 90, 180, ∞, where n i is the degree of freedom of the estimate of σ i 2 . The present tables, more accurate than previous ones, may also be applied to make similar inferences about the ratio of the means of two gamma distributions. Illustrations include applications in archaeology and telephony.