Let’s think about a significance level of .05. We can reject a null hypothesis at the .05 level if there is less than a 5 percent chance of getting an outcome at least as extreme as what we’ve observed if the null hypothesis were true. A simple example can make this much clearer. I hate to do this to you, but assume once again that you’ve been put on missing-bus duty (in part because of your valiant efforts in the last chapter). Only now you are working full-time for the researchers at the Changing Lives study, and they have given you some excellent data to help inform your work- Each bus operated by the organizers of the study has roughly 60 passengers, so we can treat the passengers on any bus as a random sample drawn from the entire Changing Lives population.-You are awakened early one morning by the news that a bus in the Boston area has been hijacked by a pro-obesity terrorist group.* Your job is to drop from a helicopter onto the roof of the moving bus, sneak inside through the emergency exit, and then stealthily determine whether the passengers are Changing Lives participants, solely on the basis of their weights. (Seriously, this is no more implausible than most action-adventure plots, and it’s a lot more educational.)