A colleague of mine was asking me to use a bubble chart to show the following
data for 2004, 2005, 2006 and 2007:

Sales Dollars
Margin Dollars
Margin as % of sales

I couldn't think of a way to display all these data on a bubble chart and
recommended a combination bar/line chart instead, with the margin % shown as
a line with its own Y2 axis.

Was I wrong and can the above data set be displayed on a bubble chart after
all?