Thanks, nice catch and that post needs to be changed... momentarily... The universe was truely from the Fortune 1000 from the list publish online... not the top 500 only...
http://money.cnn.com/magazines/fortune/fortune500/2008/full_...
Question: Using an appropriate random number generation between 1 and 1000, what is the sample size required to then estimate the total job openings on the 1000 sites?