An article in Nature reports on a study of the relationship between kinship and aggression in wasps. In a controlled experiment, the proportion of 31 brother embryos attacked by soldier wasp larvae was 0.52, whereas the proportion of 31 unrelated male embryos attacked was 0.77.15

a. What are the explanatory and response variables?

b. Construct a table of whole-number counts in the four possible category combinations, using rows for the explanatory variable and columns for the response.

c. Altogether, there were 40 attacks. If attacks had not been at all related to kinship, how many of these would be against brothers and how many would be against unrelated males?

d. Discuss the role of sample size in comparing a difference such as the difference between 0.52 and 0.77.