Description
- Use the data set you used in HW 3 and answer the following questions.
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Do two iterations of weighted least squares.
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Run robust regression (M with Huber weights) to see if influential observations were an issue
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Use Ridge Regression to see with c between .01 and .1 and provide the ridge plot
- Do plots of residual versus predicted and residual versus observed? Are they the same plot? Comment on your findings.
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Instead of doing residual analysis with residuals (for the example above) use the observed Y’s. Look at plots and tests. What do you get?