ChartGroup.SizeRepresents (Word)

Returns or sets what the bubble size represents on a bubble chart. Possible return values are xlSizeIsArea - The area of the bubble, xlSizeIsWidth - The width of the bubble.

This property can be either of the following XlSizeRepresents constants:

With ActiveDocument.InlineShapes(1) 
 If .HasChart Then 
 .Chart.ChartGroups(1).SizeRepresents = xlSizeIsWidth 
 End If 
End With