Monday, October 29, 2012

Independence, independence, independence

Multiplying probabilities without any thought is a dangerous game.  Just look at this piece in Rolling Stone, referenced in this Guardian article.
...warmest May on record for the Northern Hemisphere – the 327th consecutive month in which the temperature of the entire globe exceeded the 20th-century average, the odds of which occurring by simple chance were $3.7 \times 10^{-99}$, a number considerably larger than the number of stars in the universe.

Tuesday, October 16, 2012

Horse Racing and Coincidence

Just penned this to the BBC about why their piece on a jockey winning seven races in a single day quotes the wrong odds.
In your article on Richard Hughes winning seven races in a single day, you quote the odds of this event as being 10,168-1.  Whilst undoubtedly a fantastic achievement, these odds are incorrect, since they they ignore the fact that Mr Hughes raced in eight races that day.  The chances of him winning 7 out of 8 races (or more) is about 1,257-1, which is a bit more modest.  In particular, it seems fairly unlikely that someone would place a bet on the rider winning these particular seven races, and not the eighth.

Thursday, October 11, 2012

Fruit, Vegetables, Health and Happiness

Whilst perusing the Daily Mail today (my excuse is that it's next to the espresso machine) I saw this interesting health advice:
Forget five a day: Now scientists say you'll be healthier and happier eating seven daily portions of fruit and veg.

The phrase "scientists say" is always a red light.