AP ImagesThe Powerball lottery drawing for Saturday evening has hit a record-high estimated jackpot prize that was $800 million as of this writing, after no one won the jackpot in Wednesday's drawing. While that's a huge amount of money, buying a ticket is still probably a losing proposition. Consider the expected value When trying to evaluate the outcome of a risky, probabilistic event like the lottery, one of the first things to look at is expected value.