QUOTE (langleybaston1418 @ Thu, 28 Aug 2003 16:53:55 +0000)
This statistic [being even more pedantic] seems to depend on the premise that they were both killed. As most people in the war were NOT killed, I look forward to a revision. Upwards. After all, lots of pairs of brothers survived.
At the risk of being a raw prawn I'll weigh in here.
AIF death rate = 20% (.2). yes - 20%
So chances of first brother being killed = .2
Days in war 1550 (assuming both served for the duration). But We have to assume that the average period of service was half that i.e. 775 days.
We're talking about brothers killed on any same day, not a particular same day.
So chances of second brother being killed on that day = .2 / 775
Multiply it out we get .2 x (.2 / 775) = .0000516
or 1 chance in 19,380 of any 2 AIF brothers being killed on the same day.
Now - assuming 220,000 served (I'm not sure of the exact number), and in those days families were large and Oz was a young country) and 70% served at the same time as another brother... 220,000 x .7 / 2 77,000 pairs of brother.
77,000 / 19,380 = approx 4 chances of 2 AIF brothers killed on same day.
This figure assumes deaths were evenly spread across the calendar, but most occurred during relatively short periods of combat. Assuming this was 50% of the time and the brothers served in the same unit, we can halve these odds and say there was 1 chance in 9690 of a pair of brothers being killed on the same day. In fact I believe the odds are lower still if we consider that officers ran in families, that combat deaths were probably compressed into even more intense periods.
The really nasty statistic here is that there was a .04 chance (1 in 25) that neither would come home. But Haig wouldn't understand this, he failed arithmetic at staff college. The statistics paint a picture of postwar Europe and Empire families sitting at half-empty dinner tables.