Interesting Non Poker Thinking Problem

[David Sklansky]

Technically this should be posted on the Probability Forum but it would get fewer views there.

Why I found this question interesting was because I realized that the approximately correct answer could be deduced from pure thought. If instead, you used guesswork without thinking, you would more likely be led astray.

If a particular American citizen was selected at random and only his or her age was available to us, there would be an associated probablilty that that particular person would live at least a year. For instance a randomly selected 40 year old might have a 99.7% chance if you know only their age.

How old must the (American) person be such that based on age alone, there is less than an even money chance they will live more than a year from that moment of selection?

PLEASE answer with only a number at first. In a couple of days you can give your reason. I promise to tell you the published factual answer to this question along with the method I used to come close.