I can write

With ActiveChart
.ChartType = xlXYScatterLinesNoMarkers
.SetSourceData Source:=Sheets(1).Range(Cells(1, 1), Cells(15, 2))
End With

but this doesn't work

setrA = Sheets(1).Range(Cells(1, 1), Cells(15, 2))
With ActiveChart
.ChartType = xlXYScatterLinesNoMarkers
.SetSourceData Source:=rA
End With

Can someone explain why? [I don't want just a fix, but an understanding of
plotting procedures.

TIA,
Mike