Adding a line to an Excel plot?

[J. Kearney]

Maybe this is to specific for this group; if so, "sorry".

I've created a smooth transitioning curve plot using
Excel's Scatter Plot function; plotting Percentile

Brilliant!

Now I'd like to add a horizontal line based on one
data point to cut across the Percentile curve to show
where the average population falls on that curve.

Brilliant!

Well not so brilliant; anyone got an idea on this?

Can I use the LINEST function somehow?
If y = mx + b; the slope (m) would equal zero,
and the Y intercept (b) would be the value I input;
but how to get a horizontal line?

Thanks in advance.
Joe K

 

[JD]

I'm no expert but I would do the following:

If your data is in a column, create another column where each cell is
equal to the average of your data. Then plot a line curve of that
column of averages.

JD