All- In the last few weeks, we have received questions on how to calculate margins of error (MOE) when you add, or subtract, or divide ACS 2005 data. The Census Bureau has some instructions for applying statistical testing to ACS Data posted at http://www.census.gov/acs/www/Products/users_guide/ACS_2005_Statistical_Tes…. Using these instructions, I prepared an MS Excel template for calculating MOE for additions, subtractions, proportions, or percents (please see attached MOE.xls). I am assuming 90% CI for my calculations. There are three worksheets (one for additions/subtractions, one for proportions, and one for percents). <<MOE.xls>> Hope you find these useful. Thanks Nanda Srinivasan 202-366-5021