$640 million jackpot is hard to resist. Those who do not usually play the lottery are now playing, buying at least five tickets. The WSJ reports Megamillion sold two tickets for every adult in the country.
The probability of winning is still 1/175,711,536.
MarketPlace Radio tries to put this number in perspective by giving a list of things that are more likely to happen to us.
Chances of dating a supermodel? 1/88,0000
But there is a big difference in the definition of probability between these two scenarios that is lost.
Probability of winning MegaMillions is determined by simply counting all possible ticket numbers. This is the frequentist approach and it is correct in this case.
We cannot use the same frequentist approach for finding your chances of dating a supermodel. The 1/88,000 number is based on number of supermodels and number of men. This is relevant only if we are estimating, “what is the probability that a randomly selected man from the population is dating a supermodel?”
When you want to measure your chances of dating a supermodel you need different definition – probability as a measure of uncertainty. It is not 1/88,000. (For a more detailed discussion of this definition of probability see here.)
How can you measure this probability? If you imagined living your life 10,000 times, given all possible events that could happen and the many different choices you make, in how many such lives do you find yourself dating the supermodel? That is your probability and it is different for every individual.
On the other hand, if you do win tonight the probability of dating supermodel is 1. That is the conditional probability.