Question: A presidential candidate fears that he has a problem with women voters. His campaign staff plans to run a poll to assess the situation. They’ll randomly sample 290 women and 290 men, asking if they had a favorable impression of the candidate. Obviously, they don’t know this, but suppose the candidate has a positive image with 57% of males, but with only 51% of females.

(a) What type of sampling method are they planning to use, stratified, cluster, or systematic?

(b) Of course, sampling error means the poll won’t reflect the difference perfectly. What’s the standard error for the difference in proportion?