Email me privately (remove TRUENORTH.) , I have a sample file to do a four
parameter fir to logistic data
Then you use Solver to back solve from x to y
best wishes
--
Bernard V Liengme
Microsoft Excel MVP
http://people.stfx.ca/bliengme
remove caps from email

"Yahya" wrote in message
...
I have a chart in Excel 2007 and I want to provide a Y value (that is not
one
of the data points) and have Excel to tell me the corresponding X value
from
the chart. How can I do that?
The chart is not a straight line, so trendline won't work
Here is a picture of the chart I'm working on
http://hkoyda.blu.livefilestore.com/...x_wA/graph.JPG

Any help in this matter would be greatly appreciated.
Yahya