Unformatted text preview: (c) Test whether there is a linear relationship between x and y. Problem# 3. Refer to Airfreight breakage (Problem 1 in hw2). Without normality assumption, create the distribution of β 1 using bootstrap method and then obtain a 95% conﬁdence interval of β 1 . Compare your conﬁdence interval with the one which obtained under normality assumption. Why diﬀerent? or why similar? NOTE: use the following R commend, “sample(x,n,replace=TRUE)” and “quantile(x,probs=c(0.025,0.975)”) Problem# 4. Refer to Sales growth data (Problem 1) Check all assumptions. Perform BrownForsy test. Consider 5 or 6 diﬀerent two groups and calculate how many times you obtain constant variance. Compare this result with BrunschPagan test 1...
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 Fall '11
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 Statistics, Regression Analysis, Variance, normality assumption, Sales growth data

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