There is no way that the posterior odds are more than (1:75) toward the librarian. I would be very surprised if it were (1:10). Spelled out, The point of the example seems to be “people forget the base rate, and once you know the base rate, it’s obvious that it’s more significant than the update based on shyness”. I don’t need a source for this; it doesn’t matter whether the update based on shyness is (1:1.25) or (1:3) or something in between; any of that is dominated by the base rate.
There is no way that the posterior odds are more than (1:75) toward the librarian. I would be very surprised if it were (1:10). Spelled out, The point of the example seems to be “people forget the base rate, and once you know the base rate, it’s obvious that it’s more significant than the update based on shyness”. I don’t need a source for this; it doesn’t matter whether the update based on shyness is (1:1.25) or (1:3) or something in between; any of that is dominated by the base rate.