Extrapolation of x value from the trendline of a non-linear graph

Hi I was wondering if it is possible to extrapolate the x value from a given
y value on a scatterplot graph?
I would like to extrapolate the value from the trendline produced using the
'moving average' trendline. The trendline is sigmoidal shaped
This trendline doesn't let me produce an equation so I can't figure out the
x value that way
If I can't find the x value of the trendline, even the line formed by the
data points would be good
Thanks in advance for your help

When you use the Moving Average feature you are not really making a trend
line but just plotting the average of a number of adjacent values to smooth
the data. The data is not fitted to a mathematical model (function) so there
is no equation as you correctly point out. No equation means there is no
prediction.
best wishes
--
Bernard V Liengme
Microsoft Excel MVP
http://people.stfx.ca/bliengme
remove caps from email

"snifter" wrote in message
...
Hi I was wondering if it is possible to extrapolate the x value from a
given
y value on a scatterplot graph?
I would like to extrapolate the value from the trendline produced using
the
'moving average' trendline. The trendline is sigmoidal shaped
This trendline doesn't let me produce an equation so I can't figure out
the
x value that way
If I can't find the x value of the trendline, even the line formed by the
data points would be good
Thanks in advance for your help