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

You can find out which formula fits best your data, using Excel's "trend line" feature. Using that formula, you can calculate y for any x

1. Create linear scatter (XY) for it (Insert => Scatter);
2. Create Polynominal or Moving Average trend line, check "Display Equation on chart" (right-click on series => Add Trend Line);
3. Copy the equation into cell and replace x's with your desired x value

On screenshot below A12:A16 holds x's, B12:B16 holds y's, and C12 contains formula that calculates y for any x.

I first posted an answer here, but later found this question