Interpolating data points in Excel

Question

I\'m sure this is the kind of problem other have solved many times before.

A group of people are going to do measurements (Home energy usage to be exact). All of them wi

Answer 1

alternatively.

=INDEX(yVals,MATCH(J7,xVals,1))+(J7-MATCH(J7,xVals,1))*(INDEX(yVals,MATCH(J7,xVals,1)+1)-INDEX(yVals,MATCH(J7,xVals,1)))/(INDEX(xVals,MATCH(J7,xVals,1)+1)-MATCH(J7,xVals,1))

where j7 is the x value.

xvals is range of x values yvals is range of y values

easier to put this into code.