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Unformatted text preview: Key to the Winter 2009 Midterm 1. [3 pts ea.] True or false. If FALSE, briefly explain why. F The average of the observations made on a random sample from a population is a parameter . It is a statistic, used to estimate a parameter (the population mean, μ ). T The power of a two-sample t test increases as the pooled sample variance decreases . T A p-value much less than 0.05 in Levene’s test means that we reject the hypothesis that the two populations have equal variances. F The log transformation is always a good idea for positive-valued data. It is a good idea only if the data have a skewed distribution or an enormous range of values, or if there is reason to believe that the “effect” of the grouping variable is multiplicative, rather than additive. F If the p-value is much greater than 0.05, then we accept the null hypothesis. We fail to reject H , but we do not accept it. 2. One hundred male volunteers participated in a clinical trial. At the beginning of the study, each subject’s body weight was measured. The subjects were then randomly divided into twoeach subject’s body weight was measured....
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This note was uploaded on 11/09/2009 for the course STAT 511 taught by Professor Paulmurtaugh during the Fall '09 term at Oregon State.
- Fall '09