Calculating an interpolation
 

Hi folks,

I am using Excel 2007, and I have an interesting issue...

I have a column of numbers: 0, 500, 1000, 2000, 4000, 6000 and 8000
feet
The next column are calculated formulae for takeoff distances for the
related altitudes in column 1.

What if I would like to calculate 750 feet? Or 3000 feet?

Is there a formula I can use to interpolate between the columns?

Thanks very much,
Craig