title: Calculating Weighted Average for Multiple groups on 1 Page
body: <p>I am calculating hypothetical weighted average income by zip code. There are ~1,000 different zip codes, and I'd like to easily drag the equation for all of them. Each Zip code consists of 6 different incomes and then the number of people at that level within the zip code.</p>
  
  <p>Here is a screen grab of one group.  </p>
  
  <p><img src="https://i1116.photobucket.com/albums/k574/rybicki2/Zip-1.jpg"/></p>
  
  <p>There are approximately 1,000 of these groups directly below this one. The formula I have used in (C,3) is =(B3/$B$2)*A3.  When I use that formula, I can drag it from C3 to C8 and get the correct numbers. </p>
  
  <p>However, if I want to continue moving it down to the next group, I need the value for the total number of people to change with it. If I don't use '$' it will then just divide by the cell directly above it. </p>
  
  <p>How can I structure my formula so that I can drag it down without having to manually enter it each time. </p>
  
  <p>Thanks for your help, and if I am unclear on any details, please let me know. </p>