We did the math to see if it's worth buying a Powerball lottery ticket

The Powerball jackpot for Wednesday's drawing is up to $700 million as of 10:00 a.m. ET Wednesday. The jackpot grew after no one won Saturday's drawing. 
That is a pretty huge chunk of money. However, as we saw before Saturday's drawing when the jackpot was $535 million, taking a closer look at the underlying math of the lottery shows that it's probably a bad idea to buy a ticket.
Consider the expected value
When trying to evaluate the outcome of a ri