Draw Parallel Line Through Scatter Plot

[IronMan79]

Currently we have data that is plotted to a scatter plot along with an already defined line. Next, with a straight edge we attempt to draw a line parallel to the already defined line through the scatter points of data. We basically find two points that give us the best fit to the original line. What I attempted to do was calcualte the slope of the original line and then the slope of each combination of two points in the data set. I then subtracted the slopes, found the minimum difference and thought that would give me the line most parallel to the original. This doesn't seem to work. I'm at a loss, any advice?

[shg]

A trendline is a least-squares fit of basis functions to a set of data. Your basis function is a power series, which appears linear on your log-log plot.

Beyond that, I can't tell what you want to do.

[IronMan79]

I want excel to be able to take the original line and create a parallel line using the points in the data scatter. Or at least a line close to parallel.

[shg]

If you select Series 1 and add a power series trendline, the formula is 1.6626*x^(-1.0562).

Any multiple of that is parallel to the trendline in log-log space, so, for example, you could add another series comprising just these two points to the plot:

      ---C--- --D--- -------------E--------------
  2    2.8843 0.9800 C2: =MIN($A$2:$A$27)        
  3   38.9387 0.0627 C3: =MAX($A$2:$A$27)        
  4                  D2 and down: =3*C2^(-1.0562)

[IronMan79]

Yes but what I want is a line through "Series 1" that is parallel to the "Original" line.

[shg]

Then mutiply the y values of the "original line" by any constant.

That's probably not what you want, but you're not providing much information.

[IronMan79]

Maybe I'm not saying it correctly. The line "Original" is sort of a standard to follow. What I do now is print out the graph with the "Original" line and the "Series 1" scatter plot. Using a straight edge I find two points that most closely resemble the slope of "Original". I then use those two points to create a line. I would like Excel to find the two best points to create a parallel or near parallel line when compared to the "Original."

[shg]

See attached.

[IronMan79]

Looks great!! I really appreciate the obvious time you put into finding a solution. Now I just have to figure out what you did . All the same, can't thank you enough.