Series.BubbleSizes (Excel)

Returns or sets a string that refers to the worksheet cells containing the x-value, y-value, and size data for the bubble chart. When you return the cell reference, it will return a string describing the cells in A1-style notation. To set the size data for the bubble chart, you must use R1C1-style notation. Applies only to bubble charts.

ActiveChart.FullSeriesCollection(1).BubbleSizes = 20