I have a group of about (x,y) data points and a series of
interpolating functions that apply to particular subsets of this data.
For example, I have 'Function 1' that applies for x = 0 to 3.78,
'Function 2' that applies from x = 3.78 to 47.21, etc.

I want to use these interpolating functions to evaluate a given 'x'
value but I want the sheet to be able to recognize that, if I input a
value x = 27.76, it falls between 3.78 and 47.21 and therefore it
should use 'Function 2' to calculate the corresponding 'y' value.

I have about 20 interpolating functions and want to avoid having cells
with a huge series of 'IF' statements and was hoping someone could
point me in the direction of an alternative method.

Thanks,
Russ D.