3 ms·
I believe the worst damage to statistics is specious reasoning. My favourite chocolate promotion is Mars' '1 in 6 Wins a Free Bar' (on currently here in Oz). If
by JacobAldridge 18y ago
I believe the worst damage to statistics is specious reasoning. My favourite chocolate promotion is Mars' '1 in 6 Wins a Free Bar' (on currently here in Oz). If I buy 6 bars, most people would assume I would win once. In fact, I have only a 2/3 chance of winning a free one
1 - (5^6/6^6)
Buy 12 bars, and there's still a more than 10% chance I won't have won yet...most of the chocolate-buying government-voting lottery-praying public would be stunned.
- graywh 18y agoAnd as N approaches infinity, the probability of winning after N tries with a p=1/N approaches 1 - 1/e. (Proof left to the reader as an exercise.)
- aston 18y agoAlthough the average number of bars you'd need to buy before you win is indeed six. I think almost no one would put the odds of actually winning one by buying six at 100%.
- JacobAldridge 18y ago"Any 6 bars may not contain a free bar" You're probably right, and I hope that you are. Still, funny to note that Mars has even put this disclaimer on the bottom of their promo site! http://www.marsfreebars.com.au/ http://www.marsfreebars.com.au/