I got roughly 379 people, using current world population (http://www.worldometers.info/world-population/ http://www.worldometers.info/world-population/) and not

I got roughly 379 people, using current world population (http://www.worldometers.info/world-population/ http://www.worldometers.info/world-population/) and not including your last step of factoring out kids and elderly, because that should have been done in the (1 in 1k capable) step.