the best way to do this is let excel do the work for you. if you make a
scaterr chart of the two number and let excel create the formula which is a
trendline. follow these steps

1) Highlight all number
2) Insert Menu - Chart
3) Select Scatter Chart
4) Select Nextt until you finish. Just use default settting
5) Select any point in chart with left mouse button then press right mouse
buttton
6) Select Add Trendline - Select Linear
7) Choose Options - select Display equation on chart




"jk" wrote:

Hi,I have two columns filled with numbers,say X and Y.I want to establish a
equation between them.The equation is X=a+bY.The eqution contains two
unknowns.Can you tell me how to find a & b.