OK, so I'm trying to create a simple line graph with the average of the values rolling (aggregating) over time. So for example I have data from January to December and want to display the chart by quarter (every three month ... Q1 = Jan - Mar, Q2, Apr - Jun, etc.).
The problem I have is that Tableau is only giving the average with the Quarter only. Even when I take the average as a running total across the table or try a moving calculation of the averages, it is only aggregating within the quarter only.