You can plot both series together in an XY chart. However, an XY chart
doesn't give as nice formatting options for dates along the axis (for
example, in a line chart you can have a tick mark and label at the first of
each month, but not on an XY chart). To preserve this, make a line chart
with both series, then select one, right click on it, choose Chart Type, and
select an XY type. If necessary, format the XY chart so it is plotted on the
primary axis with the line chart.
- Jon