Diagram with constant values in the background

[taxidimu]

I am working with MSExcel 2003.
From a table I create a graph, no matter the kind of graph.
Say that the scale is 0 to 100 and the number of values is 20.
That is:
X: 1, 2, ..., 20
Y: 10, 56, ..., 2
In the backgound I need to display some constant values, for example
to show min and max acceptable values. This can be defined by a single
value for each line.
That is:
Min: 30
Max: 90
How can I define to the chart these values, without having to add more
columns (min, max, ...) to the table and fill in them, and to refer to
them in the chart?
Thank you.
tax

 

[Luke M]

In short, you can't. You need to tell the chart to look somewhere to display
a constant value.

Possible workaround:
If you've set the scale yourself, and its not automatic, perhaps you can
just draw a line and position it on the chart where you would like? You could
then select both the lines and the chart and group them together so that they
move as one.

 

[Dave Curtis]

Your max and min lines on the chart need to have a source for the data they
plot, but you can do it with a single point, rather than whole columns of
figures. Enter 30 in a cell, and add the point as a new series. The format
the series to have horizontal error bars of whatever length you want.
Repeat for your max figure of 90.

Dave

 

[Jon Peltier]

I just posted this link as an answer to another post:

http://peltiertech.com/Excel/Charts/AddLine.html

Here's another possibility:

http://peltiertech.com/Excel/ChartsHowTo/HorizBands.html

- Jon