Hi Peter,

To plot an XY (scatter) graph with two Y axes in Excel 2000, you can follow these steps:

1. Enter your data into Excel. Make sure you have two sets of data that you want to plot on the same graph, and that they have a common x-axis.
2. Select the data you want to plot. Click and drag to select both sets of data.
3. Click on the "Insert" tab in the top menu bar.
4. Click on the "Scatter" chart type in the "Charts" section.
5. Select the "Scatter with Straight Lines and Markers" option.
6. Excel will create a chart with both sets of data plotted on the same graph. However, both sets of data will be plotted on the same Y-axis.
7. To add a second Y-axis, right-click on one of the data series in the chart and select "Format Data Series" from the drop-down menu.
8. In the "Format Data Series" dialog box, select the "Axis" tab.
9. Under "Plot Series On", select "Secondary Axis".
10. Click "Close" to close the dialog box.
11. Excel will now add a second Y-axis to the chart. However, the second Y-axis will have the same scale as the first Y-axis.
12. To change the scale of the second Y-axis, right-click on the second Y-axis and select "Format Axis" from the drop-down menu.
13. In the "Format Axis" dialog box, select the "Scale" tab.
14. Under "Minimum", enter the minimum value for the second Y-axis.
15. Under "Maximum", enter the maximum value for the second Y-axis.
16. Click "Close" to close the dialog box.
17. Excel will now update the chart with the second Y-axis having a different scale than the first Y-axis.