I have the plot below as a picture and I need to remake the graphic in Excel with the proper equation.
First I printed on the paper the graphic above and I measured with ruler various values that I could see.
I inserted those values in Excel and I made a XY Scatter graphic.
Then I added a trend line and I found that a power trend line fits almost perfect to the measured points.
Excel generates automatic the equation, found as y=2.3728*xpower(-1.067).
I calculated back the y values from x values using the found equation for a double check and looks good.
As we can see on x axes we have log10 scale on original graph. I did the same on Excel.
Now, I need few things:
1) To have also a log scale on y axes as we can see in the initial graphic. I could not find how to set the chart in excel to have the same as in initial graphic and I need that. That is the most important thing.
2) On x and/or at least on y axes I would like to have the values corresponding to minor gridlines.
Excel-plot---reverse-plotting.xlsx
select the chart
select the Y axis, then right click > select Format Axis
you will see a window to format the axis
select Logarithmic scale
in the Axis Options
minimum fixed 1
maximum fixed 100
etc...