I want to calculate the R-squared value on chart with an Excel formula. But the R-squared value has to be a 2nd order polynomial.

I think R-squared has already been defined. It is a single number.
Perhaps you could restate your question. Do you mean you want to calculate
the R-squared value for a second order polynomical fit to the data?

Look at the LINEST function.

--
Regards,
Tom Ogilvy

"Metin" wrote in message
...
I want to calculate the R-squared value on chart with an Excel formula.
But the R-squared value has to be a 2nd order polynomial.

Also, for a chart, you can add a trendline and in that dialog specify the
fit to be a polynomial of order 2 and have it display the R-squared value
(second tab in the dialog).

--
Regards,
Tom Ogilvy

"Metin" wrote in message
...
I want to calculate the R-squared value on chart with an Excel formula.
But the R-squared value has to be a 2nd order polynomial.

I'm afraid the function LINEST is not the function I'm looking for.

You are mistaken about LINEST. It can be used to fit a second degree
polynomial (or higher).

You can see how Bernard Liengme solves for the coefficients of a polynomial
curve using LINEST.

http://www.stfx.ca/people/bliengme/E...Polynomial.htm


--
Regards,
Tom Ogilvy


"Metin" wrote in message
...
Yes, I mean that I want to calculate the R-squared value for a second
order polynimical fit of the data.
I'm afraid the function LINEST is not the function I'm looking for. LINEST
calculates for a straigt line. The equation for the LINEST line is y = mx +
b. The equation of the line I'm looking for has to be y = m1x^2 + m2x + b.

Thanks a lot Tom

It is solved the way of Bernard Liengme.

AWESOME! A very special thanks for that tip to Tom and especially to
Bernard.

Tom Ogilvy wrote:
I'm afraid the function LINEST is not the function I'm looking for.


You are mistaken about LINEST. It can be used to fit a second degree
polynomial (or higher).

You can see how Bernard Liengme solves for the coefficients of a polynomial
curve using LINEST.

http://www.stfx.ca/people/bliengme/E...Polynomial.htm