Here's a step-by-step guide on how to locate the point of intersection of two line graphs in Microsoft Excel 2007:

1. First, make sure that you have plotted both lines on the same graph. If you haven't done so already, select both sets of data and create a line graph.
2. Next, click on one of the data points on the first line. This will select the entire data series.
3. Right-click on the selected data series and choose "Add Trendline" from the drop-down menu.
4. In the "Format Trendline" window that appears, select the "Options" tab.
5. Check the box next to "Display Equation on Chart" and click "Close".
6. Repeat steps 2-5 for the second line.
7. Now, you should see two equations displayed on your chart, one for each line. These equations will be in the form of
   Code:

   "y = mx + b"

   , where "m" is the slope of the line and "b" is the y-intercept.
8. Set the two equations equal to each other and solve for "x". This will give you the x-coordinate of the point of intersection.
9. Once you have the x-coordinate, plug it back into one of the original equations to find the y-coordinate.
10. Finally, add a text box to your chart and type in the coordinates of the point of intersection.

That's it! You should now have the coordinates of the point of intersection displayed on your chart. Let me know if you have any questions or if there's anything else I can help you with.