Sr. Citizen Question On Adding A Trendline, Please ?

[Bob]

Hello,

Using Excel 2007, and W7.

Can't imagine what I am not doing correctly, but will blame it on old age.

I have some very simple data of blood p that I have created a Scatter
graph for. Horiz X axis is date, and vert Y axis is the blood p reading.
Plots out, and looks just fine.

Now, I want to add a Trendline to the graphed points.

So I right-click with the mouse, click on the graph (no difference if I
do this, or not, appaently), and select Add Trendline.

"Add A Trendline" comes up with the various options.

I select the color, type (linear), etc., but there is no button that
says "ADD" when you are ready to add it and close out this option page.

And, sure enough, no Trendline ever appears.

What do I have to do to actually have a linear Trendline show thru the
graphed points ?

Much thanks,
Bob

 

[joeu2004]

Using Excel 2007, and W7. [....]
So I right-click with the mouse, click on the graph
[...] and select Add Trendline.
"Add A Trendline" comes up with the various options.
I select the color, type (linear), etc., but there
is no button that says "ADD" when you are ready to
add it and close out this option page. And, sure enough, no Trendline ever
appears.

There is no way to avoid the trendline, following that procedure. Simply
closing the trendline dialog box causes the trendline to be drawn.

Perhaps it is there and you simply cannot see it. What color did you
choose?

Also, perhaps the clustering of your data or the chart type (with lines?)
makes it difficult to see the trendline.

Or perhaps the trendline is simply not where you expect to see it. See
below.

What do I have to do to actually have a linear
Trendline show thru the graphed points ?

Note that the trendline is a "best fit" regression line. Often, it does not
go through any of the original data points, unless you choose a large-degree
polynomial trendline (not recommended).

In order to validate your procedure, I suggest that you start with a graph
of "regular" data. For example, enter the dates 1/1/2012 through 12/1/2012
into A1:A12. (I am writing dates with mm/dd/yyyy format.) And enter the
number 130, 128, through 108 into B1:B12. Select A1:B12 and insert an XY
scatter chart without lines. Right-click on a data point, click on Add
Trendline, and simply close the Trendline dialog box.

Do you see the trendline now? Hopefully yes.

Now continue working with that example, morphing the options so they are
more similar to what you did with the real data. Perhaps then you will why
you are being misled into thinking the trendline was not drawn.