Apologies for using this forum but I figured this might be appropriate. I
 am trying to get the upper and lower bound at the 90% CI around shares 
of people who live and work in Palm Beach County and who live in PB 
County but work outside PB county. I am using 1 year ACS data from 2008 
and am using table B08007. I am getting a negative number under the 
square root term and obviously it cannot calculate SE. Anyone has 
pointers for a workaround or what you did when faced with something like
 this? I doubt if it can deal with imaginary numbers and i suppose you can make it zero but if anybody can elaborate on this it that would be helpful. I am 
attaching the actual XLS file and you can see a screenshot of the file 
here: <a href="http://picasaweb.google.com/krisviswanathan/ACS_STANDARD_ERROR" target="_blank">http://picasaweb.google.com/krisviswanathan/ACS_STANDARD_ERROR</a><br>


<br>TIA,<br><font color="#888888">Krishnan</font><br clear="all"><br><br><br>