Finding a best fit polynomial formula

[Sean M.]

Hello all,
Thank you in advance for your time. I am trying to use a dataset of 10 points and comparing to a second set of 10 points, and from that figure out the best polynomial fit without using a chart (this way i can use a 'predicted value' and compare it to the actual reading). Everywhere I've looked insists on using a chart, but due to the nature of spread this template is going to be to individuals who aren't very proficient with excel, having them utilize a chart is a training nightmare (some barely know how to turn on a computer).

For Example, A1:A10 has a semi-linear progression of 100 to 10000, and B1:B10 is a close approximation to A1:A10 but not quite. I found this formula but due to some proofs i have it isn't working properly:
=(INDEX(LINEST($A$1:$A$10,$A$1:$A$10^{1,2,3,4}),1)*A1^4)+(INDEX(LINEST($A$1:$A$10,$A$1:$A$10^{1,2,3,4}),1,2)*A1^3)+INDEX(LINEST($A$1:$A$10,$A$1:$A$10^{1,2,3,4}),1,3)*A1^2)+(INDEX(LINEST($A$1:$A$10,$A$1:$A$10^{1,2,3,4}),1,4)*A3^1)+INDEX(LINEST($A$1:$A$10,$A$1:$A$10^{1,2,3,4}),1,5)

[Richard Buttrey]

Please upload a workbook or a representative cut down copy, anonymised if necessary. It is always easier to advise if we can see your request in its context.

Show a before and after situation with manually calculated results, explaining which information is data and which is results, and if it's not blindingly obvious how you have arrived at your results some explanatory notes as well.

[Sean M.]

I will be happy to do so when i get home and have more access.

[Sean M.]

Please see attached. I have put in example data of what i'll use. I also show why i need it, and on the second page is the instruction that i have to follow to make it work. It's my understanding that i have to create the curves based on all polynomials and then compare to the F constant to see which is considered best fit. I just can't seem to get the formula to work right.

[Sean M.]

I don't see the attachment, did it post?
*Edit* i figured it out. nevermind :-) I didn't see the 'upload' button. all better.