Hypothesis testing for baseball data

Refer to the Baseball data set posted which reports information on the 30 Major League Baseball teams for the 2002 season.

a. At the .05 significance level, can we conclude that there is a difference in the mean salary of teams in the American League versus teams in the National League? Explain
b. At the .05 significance level, can we conclude that there is a difference in the mean home attendance of teams in the American League versus teams in the National League? Explain
c. At the .05 significance level, can we conclude that there is a difference in the mean number of wins for teams that have artificial turf home fields versus teams that have grass home fields? Explain
d. At the .05 significance level, can we conclude that there is a difference in the mean number of home runs for teams that have artificial turf home fields versus teams that have grass home fields? Use 0=real and 1=artificial. Explain

X1 X2 X3 X4 X5 X6 X7 X8 X9 X10 X11 X12 X13 X14 X15

Team League Built Size Surface Salary Salary -mil Wins Attendance Batting ERA HR Error SB Year Average
Boston 1 1912 33871 0 123505125.0 123.5 95.0 2,847,798 0.281 4.74 199 109 45 1989 512,930
New York Yankees 1 1923 57746 0 208306817.0 208.3 95.0 4,090,440 0.276 4.52 229 95 84 1990 578,930
Oakland 1 1966 43662 0 55425762.0 55.4 88.0 2,108,818 0.262 3.69 155 88 31 1991 891,188
Baltimore 1 1992 48262 0 73914333.0 73.9 74.0 2,623,904 0.269 4.56 189 107 83 1992 1,084,408
Los Angles Angels 1 1966 45050 0 97725322.0 97.7 95.0 3,404,636 0.270 3.68 147 87 161 1993 1,120,254
Cleveland 1 1994 43368 0 41502500.0 41.5 93.0 2,014,220 0.271 3.61 207 106 62 1994 1,188,679
Chicago White Sox 1 1991 44321 0 75178000.0 75.2 99.0 2,342,804 0.262 3.61 200 94 137 1995 1,071,029
Toronto 1 1989 50516 1 45719500.0 45.7 80.0 2,014,995 0.265 4.06 136 95 72 1996 1,176,967
Minnesota 1 1982 48678 1 56186000.0 56.2 83.0 2,034,243 0.259 3.71 134 102 102 1997 1,383,578
Tampa Bay 1 1990 44027 1 29679067.0 29.7 67.0 1,141,915 0.274 5.39 157 124 151 1998 1,441,406
Texas 1 1994 52000 0 55849000.0 55.8 79.0 2,525,259 0.267 4.96 260 108 67 1999 1,720,050
Detroit 1 2000 40000 0 69092000.0 69.1 71.0 2,024,505 0.272 4.51 168 110 66 2000 1,988,034
Seattle 1 1999 45611 0 87754334.0 87.8 69.0 2,724,859 0.256 4.49 130 86 102 2001 2,264,403
Kansas City 1 1973 40529 0 36881000.0 36.9 56.0 1,371,181 0.263 5.49 126 125 53 2002 2,383,235
Atlanta 0 1993 50062 0 86457302.0 86.5 90.0 2,520,904 0.265 3.98 184 86 92 2003 2,555,476
Arizona 0 1998 49075 0 62329166.0 62.3 77.0 2,059,327 0.256 4.84 191 94 67 2004 2,486,609
Houston 0 2000 42000 0 76799000.0 76.8 89.0 2,805,060 0.256 3.51 161 89 115 2005 2,632,655
Cincinnati 0 2003 42,059 0 61892583.0 61.9 73.0 1,923,254 0.261 5.15 222 104 72
New York Mets 0 1964 55775 0 101305821.0 101.3 83.0 2,827,549 0.258 3.76 175 106 153
Pittsburgh 0 2001 38127 0 38133000.0 38.1 67.0 1,817,245 0.259 4.42 139 117 73
Los Angeles Dodgers 0 1962 56000 0 83039000.0 83.0 71.0 3,603,680 0.253 4.38 149 106 58
San Diego 0 2004 42,445 0 63290833.0 63.3 82.0 2,869,787 0.257 4.13 130 109 99
Washington 0 1961 56000 0 48581500.0 48.6 81.0 2,730,352 0.252 3.87 117 92 45
San Francisco 0 2000 40800 0 90199500.0 90.2 75.0 3,181,020 0.261 4.33 128 90 71
St Louis 0 1966 49625 0 92106833.0 92.1 100.0 3,542,271 0.270 3.49 170 100 83
Florida 0 1987 42531 0 60408834.0 60.4 83.0 1,852,608 0.272 4.16 128 103 96
Philadelphia 0 2004 43500 0 95522000.0 95.5 88.0 2,665,304 0.270 4.21 167 90 116
Milwaukee 0 2001 42400 0 39934833.0 39.9 81.0 2,211,323 0.259 3.97 175 119 79
Chicago Cubs 0 1914 38957 0 87032933.0 87.0 79.0 3,100,092 0.270 4.19 194 101 65
Colorado 0 1995 50381 0 48155000.0 48.2 67.0 1,914,385 0.267 5.13 150 118 65