For the "airpollution50.txt" data, take Mortality as the response variable and Education Rain _NonWhite NoxPot SO2POT HCPot

as possible predictors, use the glmselect procedure and the following criteria/strategies to select model.

(1) Use the backward strategy, and select=BIC to select model.

(2) Use the forward strategy, and select=AIC to select model.

(3) Are the two selected models the same? If not, how they differ? Can you do hypothesis test to compare these two models? If they are the same, draw the residual plots and comment whether you observe any severe violation of model assumptions.

Mort Rain Educ NonWht HC NOx SO2 City

921.87 36 11.4 8.8 21 15 59 Akron, OH

997.87 35 11 3.5 8 10 39 Albany-Schenectady-Troy, NY

962.35 44 9.8 0.8 6 6 33 Allentown, Bethlehem,PA-NJ

982.29 47 11.1 27.1 18 8 24 Atlanta, GA

1071.29 43 9.6 24.4 43 38 206 Baltimore, MD

1030.38 53 10.2 38.5 30 32 72 Birmingham, AL

934.7 43 12.1 3.5 21 32 62 Boston, MA

899.53 45 10.6 5.3 6 4 4 Bridgeport-Milford, CT

1001.9 36 10.5 8.1 18 12 37 Buffalo, NY

912.35 36 10.7 6.7 12 7 20 Canton, OH

1017.61 52 9.6 22.2 18 8 27 Chattanooga, TN-GA

1024.89 33 10.9 16.3 88 63 278 Chicago, IL

970.47 40 10.2 13 26 26 146 Cincinnati, OH-KY-IN

985.95 35 11.1 14.7 31 21 64 Cleveland, OH

936.23 36 11.4 12.4 6 4 16 Dayton-Springfield, OH

871.77 15 12.2 4.7 17 8 28 Denver, CO

959.22 31 10.8 15.8 52 35 124 Detroit, MI

941.18 30 10.8 13.1 11 4 11 Flint, MI

871.34 31 10.9 5.1 5 3 10 Grand Rapids,MI

971.12 42 10.4 22.7 8 3 5 Greensboro-Winston-Salem-High Point,NC

887.47 43 11.5 7.2 7 3 10 Hartford, CT

952.53 46 11.4 21 6 5 1 Houston, TX

968.67 39 11.4 15.6 13 7 33 Indianapolis, IN

919.73 35 12 12.6 7 4 4 Kansas City,MO

844.05 43 9.5 2.9 11 7 32 Lancaster, PA

861.26 11 12.1 7.8 648 319 130 Los Angeles,Long Beech, CA

1006.49 50 10.4 36.7 15 18 34 Memphis, TN-AR-MS

861.44 60 11.5 13.5 3 1 1 Miami-Hialeah, FL

929.15 30 11.1 5.8 33 23 125 Milwaukee, WI

857.62 25 12.1 2 20 11 26 Minneapolis-St. Paul,MN-WI

961.01 45 10.1 21 17 14 78 Nashville, TN

923.23 46 11.3 8.8 4 3 8 New Haven-Meriden,CT

1113.16 54 9.7 31.4 20 17 1 New Orleans,LA

994.65 42 10.7 11.3 41 26 108 New York,NY

1015.02 42 10.5 17.5 29 32 161 Philadelphia, PA-NJ

991.29 36 10.6 8.1 45 59 263 Pittsburgh, PA

893.99 37 12 3.6 56 21 44 Portland, OR

946.19 41 9.6 2.7 11 11 89 Reading, PA

874.28 32 11.1 5 7 4 18 Rochester, NY

953.56 34 9.7 17.2 31 15 68 St. Louis,MO-IL

839.71 10 12.1 5.9 144 66 20 San Diego,CA

911.7 18 12.2 13.7 311 171 86 San Francisco,CA

790.73 13 12.2 3 105 32 3 San Jose,CA

899.26 35 12.2 5.7 20 7 20 Seattle, WA

904.16 45 11.1 3.4 5 1 20 Springfield, MA

950.67 38 11.4 3.8 8 5 25 Syracuse, NY

972.46 31 10.7 9.5 11 7 25 Toledo, OH

912.2 40 10.3 2.5 5 2 11 Utica-Rome, NY

967.8 42 12.3 25.9 65 28 102 Washington, DC-MD-VA

823.76 28 12.1 7.5 4 2 1 Wichita, KS