4 Replies Latest reply on Apr 25, 2017 5:14 AM by Tony Durst

    Trouble with Joined Data in Calculation

    Tony Durst

      Hi all,

       

      I'm new to Tableau, so I hope someone has encountered this before. I'm working with some crime data from Chicago's data portal. I have record level crime report data that I have classified into Arrests, No Arrests and Combined. I brought in population for all of Chicago for the ten years that I'm working with. I joined the data on Year. I want to calculate total arrests divided by population (per 100k). To get a crime rate stat. So for example, 25,000 burglaries / (2.7M people/100k) is a burglary rate of 925.9 per 100k residents.

       

      The problem is that when I bring in population per year I need to choose a measure. I choose avg wanting an average per year which should be the population for that year as ever year as a constant population number. What I get though is an average across all years no per year. I've tried using LOD to solve but can't crack the code. Any helpful ideas would be much appreciated!