it's actually a percentage i think, so if you have 4.7 percent blood-alcohol level it means 4.7 percent of your blood is alcohol

which would probably kill you.
.47 percent is significantly less
the highest i remember blowing is a .285 when I used to drink alot. I don't really see how you could remember much higher than that, because that was right on the edge of blacking out for me. I know I did a little bit of time traveling, but I was still conscious if rather.. drunk. Tht girl was probably exagerrating alot unless the police give out smiley face stickers with your blood alcohol level so you can remember later (that's a really good idea, maybe with scientificly calculated data on how many drinks you had at your weight with more stickers that are like martini glasses).
that was off of a bottle of knob creek ;9 i think that's 90 or 100 proof whiskey; pretty bottle, smooth taste.