Figure 3.

National Retail Data Monitor: Sales of pediatric electrolytes in Philadelphia on May 17, 2003. The color coding indicates the level of sales of pediatric electrolytes for each zip code, relative to historical trends for that zip code. Most of the zip codes are colored green (the lighter shade) indicating that sales are within 0.5 standard deviations of expected. A few zip codes are colored blue (slightly darker shade), indicating sales are 0.5 to 2.0 standard deviations higher than expected. There are no clusterings of blue zip codes (or yellow, orange, or red areas) that would be indicative of more anomalous sales activity perhaps warranting investigation.