Not much is certain in this life. We wake up more certain of some things than of others, though: Will we make it through the day or be run over by a bus? Will it rain this afternoon? What are the chances I'll win the lottery? Rather than assume that there are solid, immutable answers to any of these questions we turn to statistics to answer questions about probabilities as well as how certain we are of what our research indicates. Uncertainty is never truly eliminated; rather, our goal is to manage it.