Excel plot digitizer

Question

Is there any plot digitizer usable in Excel? I have discrete points (values X and Y) and I have to create graph from these - Excel can create the "mean curve" (I am sorry, I am not a native speaker so I might not use the right terms). My problem is: I need to find Y valus for any X from this graph (it shoud work automatically while changing the X input, because the Y value is used for subsequent calculations). As I have no equation of the graph, it is impossible to just evaluate the values from the equation. So is there any way that would enable to just choose X and output in another field would be the appropriate Y value? Or do you know another software that could be used for creating such graph as in Excel and would have such function? Sorry for my english and thanks in advance!

Answer 1

In order to extract the equation behind an Excel calculated trendline, you just need to to right-click on the line/curve and select "Display Equation on Chart":

Then, you can create a formula matching this equation by hand.

Answer 2

You can use Excel to fit a trend line or curve to your data (also known as a regression; is that what you're referring to when you say "mean curve"?), and then plug x-values into the equation of said trend line/curve to get y-values back.