James checks the weather report on his smartphone. It says “a 30 percent chance of rain tomorrow.” But 30 percent of what? He assumes it means that it will rain tomorrow 30 percent of the time. But he’s not really sure, so asks his friends. Emma believes it will rain tomorrow in 30 percent of the area. Luna thinks it will rain on 30 percent of the days for which this prediction has been made. And Leo says it means that three meteorologists believe it will rain, and seven do not. Who is right?