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

[snifter]

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

 

[Bernard Liengme]

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