Question

ch 9* the community intervention trial for smoking cessation asked whether a community - wide advertising campaign would reduce smoking. the researchers located 11 pairs of communities, with each pair similar in location, size, economic status, and so on. to decide which community in each pair should get the advertising campaign, it is best to
choose the community that will help pay for the campaign.
choose the community with a mayor who will participate.
toss a coin.

Explanation:

In experimental design, to avoid bias when assigning treatments (here, the advertising campaign) to similar groups (the community pairs), randomization is key. Tossing a coin is a simple randomization method that ensures each community in a pair has an equal chance of getting the campaign, minimizing confounding factors. Choosing based on payment or mayor participation would introduce bias, as those factors aren't related to the smoking cessation effect being studied.

Answer:

toss a coin.