You may want to add a trend line to the graph and show equation. Then use
the equation to get the results you are looking for results

Use Scatter chart rather than line chart

Right click on any point on the graph and choose "Add Trand Line". find
best results by getting an option that best resembles the actual data.

Go to Options Tab - Display Equation on Chart.

You can adjust the X - Intercept to get better reults.




"WH99" wrote:

Is there a way macro can read line graphs?
I have a graph with temperature along the bottom, weight along the left side
and in the the graph area there are several diagonal lines as pressure
altitude. By entering the graph at Temperature going straight up into the
graph to the correct pressure altitude then move left horizontally left and
that will give you the answer (weight).

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WH99