To 308 wind speed miles per hour 200 232 02 to 59

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10 to 308Wind-speed (miles per hour)2.002.32-0.2 to 5.9* (traffic count / traffic speed [in miles per hour])
STATISTICS104FINALEXAMSOLUTIONS9An experienced investigator from the Environmental Protection Agency (EPA) suggested adding a“wind-squared” (wind x wind) term to the multiple regression model.Results of this secondmultiple regression analysis and the scatterplot of CO by wind-squared are given below.b)(3 points)Based on the above regression and scatterplot, what would you concluderegarding the transport effect of wind on carbon monoxide?
c)(2 points)Based on the above two normal probability plots and the r-squared values forthese two regression models, what would you conclude regarding the relative merits of these twomodels?Explain your answer.
STATISTICS104FINALEXAMSOLUTIONS10A4681012Y468101214XB246810Y468101214XC4681012Y468101214XD68101214Y5101520X0.2.4.6.81Leverage0.05.1.15.2.25Normalized residual squared6.(15 points total)In 1973 Frank Anscombe created 4 regression datasets to point out theneed to check diagnostics when conducting regression analyses.Each of the 4 artificial datasetscontained 11 observations and had the same correlation coefficient between Y and X (r = 0.816).Further, each of the 4 datasets had exactly the same least squares line (ŷ= 3 + 0.5 X).Scatterplots ofthe 4 datasets with least squares lines are given below and are labeled A, B, C and D.a.(3 points)Which dataset corresponds to the following leverage-vs.-squared-residual plot?(Circle one)Dataset A, Dataset B, Dataset C, orDataset DGive a statement supporting your answer.The single point that is an outlierhas a zero residual – indicatingit is on the least squares line.All other points have no leverage.
STATISTICS104FINALEXAMSOLUTIONS11

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Term
Spring
Professor
MichaelIsaacParzen

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