ECOL608 Statistics Assignment - 2018
This assignment is worth 40% of your final grade. Please submit your assignment as a single Word
document using the assignment upload link on the course website. This assignment is due June
8th at 5PM. We will have a class session where you can work on it, but you will have to do most
of the work in your own time.
Problem 1: Consider the data obtained from a random sample of male grey kangaroos examining
the relationship between nasal length (X: measured in mm) and nasal width (Y: measured in mm).
Reference: Australian Journal of Zoology, Vol. 28, p607-613
X Y
609 241
629 222
620 233
564 207
645 247
493 189
606 226
660 240
630 215
672 231
778 263
616 220
727 271
810 284
778 279
823 272
755 268
710 278
701 238
803 255
855 308
838 281
830 288
864 306
635 236
565 204
562 216
580 225
596 220
597 219
636 201
559 213
615 228
740 234
677 237
675 217
629 211
692 238
710 221
730 281
763 292
686 251
717 231
737 275
816 275
Using R and the techniques you have learned in this course plot this relationship and use the
appropriate statistical methods to characterise the relationship and its significance. Be sure to
explain your reasoning for each step in the analysis. Hint: Remember that there are four steps to
fitting a statistical model (see your notes!).
Problem 2: The following data represent weights (pounds) of a random sample of professional
football players on the following teams. X1 = weights of players for the Dallas Cowboys; X2 =
weights of players for the Green Bay Packers; X3 = weights of players for the Denver Broncos; X4
= weights of players for the Miami Dolphins; X5 = weights of players for the San Francisco Forty
Niners. Reference: The Sports Encyclopedia Pro Football
X1 X2 X3 X4 X5
250 260 270 260 247
255 271 250 255 249
255 258 281 265 255
264 263 273 257 247
250 267 257 268 244
265 254 264 263 245
245 255 233 247 249
252 250 254 253 260
266 248 268 251 217
246 240 252 252 208
251 254 256 266 228
263 275 265 264 253
248 270 252 210 249
228 225 256 236 223
221 222 235 225 221
223 230 216 230 228
220 225 241 232 271
Again use R to determine whether there are any significant differences between the teams.
Hint: Don’t forget the four steps!