Okay, with both curves in one chart.
You can see the coordinates better in the picture. Here's the file if you like: <a href="http://northernocean.net/etc/mrexcel/20110207_file.zip">Sample File (zip)</a>
Sample Demand Curve:
<img alt="chart" src="http://northernocean.net/etc/mrexcel/20110207_demand_chart_3.png" />
These are chart options for the above scatter (xy) chart:
<img alt="chart" src="http://northernocean.net/etc/mrexcel/20110207_demand_chart_4.png" />
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