I have added a 'totals' column to a chart to display the average of all percentage values from each row by clicking 'show totals'. However, the 'totals' column is not showing the correct mean average of the values. For example, in one row, I have three percentage values: 99.1%, 95.4%, and 87.1%. The totals column shows a value of 94.2%, but the correct average should be 93.9%. How can I adjust the chart to display the correct average?
Average will display the average of all underlying rows, not the mean of the averages (which is almost never desirable, but I guess in your specific situation it might be?). For regular tables, you can change the way it behaves using the Totals Function option in each individual measure.