An urban entomologist did an experiment to assess the effectiveness of five different brands of mosquito repellent and an untreated control. Thirty volunteers were assigned at random to six groups of five. Each individual had repellent applied to their left arm, which was then inserted into a chamber containing 200 starved female mosquitoes. The numbers of bites on each person's arm after one hour of exposure are given below.
(a) Is the analysis Model I or Model II?
(b) Run a single-factor ANOVA on the data. Is there a significant difference among treatments?
(c) Run an a posteriori Tukey test. Which repellent would you recommend? Are there any you definitely would not recommend?