How do I interpolate within a 2d dataset?

I didn't really like the AnimationCurve solution Mike posted below. I suppose it could have worked, but it was not intended for what I was attempting to do -- evaluate data. So I wrote a simple function that essentially mimics what Matlab's interp1 does.

 function InterpX(x){  //linearly interpret a Y value given an X input
     arraylength = dataPairs.length - 1;  // get # of rows of my array
     //Debug.Log(arraylength);
 
     for (var i = 0; i < arraylength; i++){  //start for loop to look through each data point
             var index = i; //save current value of i for use later since using i directly fucks it up
                         
             //get x and y value for i position
             var NumA = parseFloat(dataPairs[i][0]);
             var NumC = parseFloat(dataPairs[i][1]);
             
             //get x and y value from data for i + 1 position
             if(index < arraylength){   
             var NumB = parseFloat(dataPairs[index + 1][0]);
             var NumD = parseFloat(dataPairs[index + 1][1]);}
             
             //find which data points our x input falls between
             if (NumA < x && x < NumB){
                     var DeltaAB = Mathf.Abs(NumB - NumA); //Get difference between the two x values
                     var DeltaxAB = x - Mathf.Min(NumA,NumB); //Our input minus whichever value is lowest
                     var Ratio = DeltaxAB/DeltaAB; // ratio of our input to the span between A and B
                     Debug.Log(x + ' is between ' + NumA + ' and ' + NumB);
                     
                     var DeltaCD = Mathf.Abs(NumD - NumC); //Get difference between the two y values
                     var y = (DeltaCD * Ratio) + Mathf.Min(NumC,NumD); //Linear interpolation of y
                     Debug.Log('y:' + y);
                     
                     break; //end i loop
                     }
     }
 } //end function InterpX

There may be more efficient ways to have written this function -- and I'm open to suggestions to improve it -- but all that really matters is that I can now process some data :D

I wanted to post this in case anybody else is ever looking for a similar function. Of course the prerequisite prior to calling the function is that you have imported data from a file to an array which is called dataPairs here.

Thanks again for the help, Mike! Much appreciated.