
Accession Number : ADA023937
Title : Inferential Techniques for Weibull Populations. II.
Descriptive Note : Final rept. 15 Apr 7415 Jun 75,
Corporate Author : SKF INDUSTRIES INC KING OF PRUSSIA PA
Personal Author(s) : McCool,John I.
Report Date : JUN 1975
Pagination or Media Count : 76
Abstract : Two test statistics are examined and shown to have the required properties to serve as a test of the null hypothesis that k 2parameter Weibull populations, having a common but unknown shape parameter, have a common scale parameter. The test statistics are the ratios of the maximum likelihood (ML) shapeparameter estimate derived on the assumption that the scale parameters differ to (1) the ML shapeparameter estimate calculated using the earliest failure in each sample and to (2) the ML shapeparameter estimate calculated after combining the k data samples. The theory for drawing inferences on Weibull parameters in the presence of a single competing Weibull failure mode having the same (but unknown) shape parameter as the primary mode is generalized to the case of k competing modes. An illustration is given of the construction of a joint confidence region for the proportion of failures due to mode j and a percentile of the distribution of failure due to mode j when only that mode operates.
Descriptors : *Weibull density functions, *Statistical samples, *Statistical tests, Estimates, Analysis of variance, Monte Carlo method, Population(Mathematics), Random variables
Subject Categories : Statistics and Probability
Distribution Statement : APPROVED FOR PUBLIC RELEASE