The effect of Benzedrine on the heart rate of dogs (in beats per minute) was examined in an experiment on 14 dogs chosen for the study. Each dog was to serve as its own control, with half of the dogs assigned to receive Benzedrine during the first study period and the other half assigned to receive a placebo (saline solution). All dogs were examined to determine the heart rates after 2 hours on the medication. After 2 weeks in which no medication was given, the regimens for the dogs were switched for the second study period. The dogs previously on Benzedrine were given the placebo, and the others received Benzedrine. Again, heart rates were measured after 2 hours. The following sample data are not arranged in the order in which they were taken but have been summarized by regimen. Use these data to test the research hypothesis that the distribution of heart rates for the dogs when receiving Benzedrine is shifted to the right of that for the same animals when on the placebo. Use a one-tailed Wilcoxon signed-rank test with α = .05.

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Dog Placebo Benzedrine Dog Placebo Benzedrine 250 271 305 319 258 8 296 285 301 243 245 10 298 308 252 250 11 310 320 266 268 12 286 293 6 272 278 13 306 305 293 280 14 309 313 1234 So7