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## QTM SI Handout 4/23/15Instructor: Dr. McGee SI: Cleo LiEmail: yixin.li@emory.eduExam 4: Correlation,

QTM SI Handout 4/23/15Instructor: Dr. McGee SI: Cleo LiEmail: yixin.li@emory.eduExam 4: Correlation, Linear & Multiple Regression, one-way/repeatedmeasures/factorial ANOVA, and Wilcoxian Rank Sum & Kruskal-Wallis H Test.Correlation:1. What does the correlation coefficient tell us?2. What is the possible range of values for a correlation coefficient?3. What is the best way to graphically display correlational data?4. For 14 baseball teams, the correlation with number of wins in the regular season is0.51 for shutouts, 0.61 for hits made, -0.10 for runs allowed and -0.56 for homerunsallowed. Which variable has the weakest linear association with number of wins?5. Which has a stronger correlation, A or B? Why?*when describe the scatter-plot, consider 1. strong/weak, 2. positive/negative, 3.linearity, and 4. homoscadacity/ heteroscadacity.Simple Linear Regression: (predict)1. The Atlanta based Center for Crime Analysis and Prevention designs a study todetermine if the number of high school dropouts can be used to predict the numberof crimes committed by adolescents within Fulton County. The average number ofdropouts per year in a Fulton County County school district is 76 with a standarddeviation of 7.4 and the average number of crimes committed by adolescents is 49with a standard deviation of 5.2. If a linear regression model gives R=0.84,a. Find the residual for a school district in which there are 68 dropouts and 39 crimescommittedbyadolescents.b. Explain your result.2. Research Question: âAre Honda Civicâs with lower mileage worth more than thosewill high mileage?âPredictor variable: mileageResponse variable: car priceŷ = 24,723 + 0.17xt=-4.09 (p-value