Hi Claire,

No need to apologize, happy to help! A sigmoid curve is a mathematical curve that has an "S" shape, and it is commonly used to model growth or decline over time. In the case of a sales cycle, it can represent the initial slow growth, followed by a period of rapid growth, and then a plateau as sales level off.

To plot a sigmoid curve in Excel 2003, you can follow these steps:

1. Enter your data into two columns: one for the time period (e.g. months, years) and one for the sales figures.
2. Select both columns of data and click on the "Insert" tab in the top menu.
3. Click on the "Scatter" chart type and select the one with smooth lines and markers.
4. Your chart should now be displayed. Right-click on the chart and select "Select Data".
5. Click on the "Add" button to add a new series.
6. In the "Edit Series" window, enter a name for the series and select the time period column for the "X values" and the sales figures column for the "Y values".
7. Click "OK" to close the window and your new series should be added to the chart.
8. Right-click on the new series and select "Change Series Chart Type".
9. Select the "S Curve" chart type and click "OK".
10. Your chart should now display a sigmoid curve.

To plot several points along the curve, you can add additional data points to your original data and include them in the chart. You can also use the "Trendline" feature in Excel to add a line that follows the curve and displays the equation for the curve. To do this, right-click on the curve and select "Add Trendline". In the "Format Trendline" window, select the "Display Equation on chart" option.