Numbers
Modify chart data in Numbers on Mac
You can modify a chart’s data references (numbers, dates, or durations) at any time. You can add and remove an entire data series, or edit a data series by adding or deleting specific data from it.
Note: Some options may be different for pivot charts.
While you’re editing a chart’s data references, a dot appears on the tab of each sheet that contains data used in that chart.
If you can’t edit a chart, it may be locked. Unlock it to make changes.