Lognormal, Weibull & Heavy-Tailed Cauchy Distributions

Compare lognormal, Weibull and Cauchy models for positive measurements, reliability lifetimes and heavy-tailed errors. Prerequisites: normal probabilities, logarithms, continuous densities and moments. Work from parameter interpretation to survival calculations, conditional lifetime reasoning and model selection. Explanations distinguish log-scale summaries from original-scale summaries and examine when conventional moments and averaging arguments fail.

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Further reading: PDF and Common Statistics, PDF, CDF, survival and hazard, PDF, CDF and Common Statistics.