I'm struggling to add a reference line made up of various points on to a dual axis. I am showing an age profile using horizontal bars with the 'area' option chosen in the mark box. This is because I have the number of people in an age band and not individual records that Tableau can use. I am trying to create a reference line made up of 10 values which are my averages.
Here is a print screen of what I have so far:
I have my actual values I want (% of ...) and I have my reference values (av % of ...). I've created a dual axis with synchronization, but I can't think of a way to join the two x-axes togethor due to the way the data is.