Is it defense or offense that wins football games? Consider the following portion of data, which includes a teams winning record (Win in %), the average number of yards gained, and the average number of yards allowed during the 2009 NFL season.

Team	Win	Yds Made	Yds Allowed
Arizona Cardinals	62.50	344.40	346.40
Atlanta Falcons	56.30	340.40	348.90
Baltimore Ravens	56.30	351.20	305.00
Buffalo Bills	37.50	273.90	340.60
Carolina Panthers	50.00	331.10	315.80
Chicago Bears	43.80	310.30	337.80
Cincinnati Bengals	62.50	309.10	301.40
Cleveland Browns	31.30	260.20	389.30
Dallas Cowboys	68.80	399.40	315.90
Denver Broncos	50.00	341.40	315.00
Detroit Lions	12.50	299.00	392.10
Green Bay Packers	68.80	379.10	284.40
Houston Texans	56.30	383.10	324.90
Indianapolis Colts	87.50	363.10	339.20
Jacksonville Jaguars	53.80	336.60	352.30
Kansas City Chiefs	25.00	303.20	388.20
Miami Dolphins	43.80	337.60	349.30
Minnesota Vikings	75.00	379.60	305.50
New England Patriots	62.50	397.30	320.20
New Orleans Saints	81.30	403.80	357.80
New York Giants	50.00	366.00	324.90
New York Jets	56.30	321.00	252.30
Oakland Raiders	31.30	266.10	361.90
Philadelphia Eagles	68.80	357.90	321.10
Pittsburgh Steelers	56.30	371.30	305.30
Saint Louis Rams	6.30	279.38	327.00
San Diego Chargers	81.30	360.06	326.40
San Francisco 49ers	50.00	290.75	356.40
Seattle Seahawks	31.30	316.80	372.80
Tampa Bay Buccaneers	18.80	287.50	365.60
Tennessee Titans	50.00	351.40	365.60
Washington Redskins	25.00	312.50	319.70

a-1. Estimate two simple linear regression models, where Model 1 predicts the winning percentage based on Yards Gained and Model 2 uses Yards Allowed. (Negative values should be indicated by a minus sign. Round your answers to 4 decimal places.)

a-2. Compare the two simple linear regression models.

b-1. Estimate a multiple linear regression model, Model 3, that applies both Yards Gained and Yards Allowed to forecast winning percentage. (Negative values should be indicated by a minus sign. Round your answers to 4 decimal places.)

b-2. Is this model an improvement over the other two models?

multiple choice

• Yes since Model 3 has a lower R² than Models 1 and 2.

• Yes since Model 3 has a lower adjusted R² than Models 1 and 2.

• Yes since Model 3 has a higher R² than Models 1 and 2.

• Yes since Model 3 has a higher adjusted R² than Models 1 and 2.