You can find routines in the archives or on the internet to calculate
piecewise interpolated values. Use these to calculate the Y1 values and Y2
values, then compute your ratios. Once you set up one worksheet with the
formulas, you can reuse it for additional data sets.

- Jon
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Jon Peltier, Microsoft Excel MVP
Tutorials and Custom Solutions
http://PeltierTech.com
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"labview1958"
wrote in message
...

Graph 1.(measurement)
(1,3), (3,5), (5, 9), (7, 13)

Graph 2.(measurement)
(2,3), (4,7), (6, 11), (8, 19)


Graph 3.(calculation)
(1, y1/y2), (2, y1/y2), (3, y1/y2), (4, y1/y2)

where y1 and y2 is obtained by first drawing a trendline, finding it's
equation and then substituting the x value to find the corresponding y
value. The two y values corresponding to a particular x is then found.
The ratio of the two y values is then calculated. Finally a third graph
is drawn.

The whole process is tedious. Is there a simpler way?


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labview1958
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