From that article:

According to the National Crime Victimization Survey, the most recently available rape victimization rate is 0.4 per 1000 people. Applying the 0.91 percentage of female rape victims corrects this to 0.364 per 1000,

0.364 female rape victims per 1000 people total, or 0.364 female rape victims per 508 women. If he's going to say stuff like ‘1/7 isn't compatible with 1/6’ (seriously -- are we talking about watchmaking?), he shouldn't be making factor-of-two mistakes himself.

EDIT, 21 Sep 2013: And of course 0.4 x 0.91 = 0.364 is most likely false precision.

Seriously imagine if the prevalence of some other serious crime (such as burglary, mugging, or murder)

Murder obviously doesn't sound comparable, and ISTM it's not like people living where the rate of mugging is of the order of 0.1 per person per lifetime are that terrorized. (Sicilians do rally against the mafia once in a while.)

EDIT: I've started to read the comments to the article you linked to and... Wow. Suffice it to say that I am appalled that the same person as the editor of the Jargon File would be that bad at middle-school maths.