The table below shows the numbers of male and female rattlesnakes caught at two different sites, B and G. Assume that the snakes caught at a site can be regarded as a random sample from the population of all snakes at the site.

We want to know whether there is an association between site and sex. Site is the explanatory variable and sex is the response variable.
a. Explain why we use conditional proportions to evaluate the association.
b. Explain why we look at the proportion of females and proportion of males conditional on the site rather than the proportion from each site conditional on the sex.

c. Reasoning informally, do you think the data show evidence of an association between site and sex? Explain.

Transcribed Image Text:

Total Site B Site G 23 12 12 Female 11 Male 21 31 Total 33 21 54