Question: A study reported in the Journal of the American Medical Association investigated the cardiac demands of heavy snow shoveling. Eight healthy men underwent exercise testing with treadmill and a cycle ergometer modified for arm cranking. The men then cleared two tracts of heavy, wet snow by using a lightweight plastic snow shovel and an electric snow thrower. Each subject's heart rate, blood pressure, oxygen uptake, and perceived exertion during snow removal were compared with the values obtained during treadmill and arm- crank ergometer testing.
Suppose the following table gives the heart rates in beats per minute for each of the eight subjects. At the .05 level of significance, test for any significant differences.
Subject Treadmill (Arm-Crank Ergometer) Snow Shoved Snow Thrower
1 177 205 180 98
2 151 177 164 120
3 184 166 167 111
4 161 152 173 122
5 192 142 179 151
6 193 172 205 158
7 164 191 156 117
8 207 170 160 123