Young people on the lookout for prospective husbands or wives often claim that certain cities have more women or more men. To study this issue, you sample the voter rolls in three cities looking for...

Young people on the lookout for prospective husbands or wives often claim that certain cities have more women or more men. To study this issue, you sample the voter rolls in three cities looking for people who are between 20 and 30 years of age and single. Here are the numbers of those you find, by gender:

Your question might be addressed in the following way: An independence model would mean that the proportions of men and women did not depend on which city you looked in. So you should define and find standard estimates for an independence model. Then build a table of expected values. Comment on what the comparison between the two tables says about the question you began with.