Chapter 8.2, Problem 4Q

For Questions 8.2.1-8.2.12 use the flowchart in Figure 8.2.4 to identify the experimental designs represented. In each case, answer whichever of the questions on p. 427 are necessary to make the determination.

Male cockroaches can be very antagonistic toward other male cockroaches. Encounters may be fleeting or quite spirited, the latter often resulting in missing antennae and broken wings. A study was done to see whether cockroach density has any effect on the frequency of serious altercations. Ten groups of four male cockroaches (Byrsotria fumigata) were each subjected to three levels of density: high, intermediate, and low. The following are the numbers of “serious” encounters per minute that were observed $\left(16\right)$.

Group	High	Intermediate	Low
1	0.30	0.11	0.12
2	0.20	0.24	0.28
3	0.17	0.13	0.20
4	0.25	0.36	0.15
5	0.27	0.20	0.31
6	0.19	0.12	0.16
7	0.27	0.19	0.20
8	0.23	0.08	0.17
9	0.37	0.18	0.18
Average	0.25	0.18	0.20