Hi,
Since you are calling your equation,the 'logarithmic REGRESSION line', it
seems to me that you obtained that equation by fitting the function a + b
ln(x) to some existing X,Y-data. If that is the case and you already have
the XY-plot of the data, all you have to do is to add a logarithmic trendline
to it.
Right-click on a data-point in the graph --> "Add Trendline" --> under
'Type' select "Logarithmic" and under 'Options' check "Display Equation on
Chart" --> "OK".
This adds the regression line to the existing plot of your data.
If, on the other hand, you want to just make a plot of y = 1.649+1.968
ln(x), you have to create a column of x-values, and calculate a column of
y-values using the equation, and make an XY-plot of those values (as
suggested Jon Peltier).
Regards,
B. R. Ramachandran