Thanks, I think I get it on a superficial level. The British seemed to have some pretty useful statisticians during WWII. See this also : http://www.dur.ac.uk/s

Thanks, I think I get it on a superficial level. The British seemed to have some pretty useful statisticians during WWII. See this also : http://www.dur.ac.uk/stat.web/bomb.htm http://www.dur.ac.uk/stat.web/bomb.htm EDIT : So there's about a fifty fifty chance that the second observation will be bigger than the first. After the second observation the range of possible future observations will be divided into 3 zones, 1 below the lowest of the previous 2 observations 1 above the higher and 1 between the two previous observations, so there is now only a 1/3 possibility of the next observation being above the higher of the 2 previous observations. Next time that drops to 1/4 then 1/5, so that's how the standard deviation decreases proportional to 1/n