Here's a shocker: people don't understand the probabilities in weather forecasts:
...only half the population understands what a precipitation forecast means well enough to make a fully informed answer, a new study finds.
If, for example, a forecast calls for a 20 percent chance of rain, many people think it means that it will rain over 20 percent of the area covered by the forecast. Others think it will rain for 20 percent of the time, said Susan Joslyn, a cognitive psychologist at the University of Washington who conducted the study.
So much for no child left behind. Even the basics elude most of them.