Thanks for the suggestions. I see from an old thread that I missed (LINEST
maximum number of predictor variables 2/15/2005 3:35 PM PST ) that the 16
limit in XL is more than a hard-code limit; the method of calculation
apparently breaks down much before the limit of 16 is reached. Since I have
MATLAB, I will just export my data and compute the regression there. Thanks
to all for the help.

"Bernard Liengme" wrote:

You may need to buy SPSS!

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Bernard V Liengme
www.stfx.ca/people/bliengme
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"Ken" wrote in message
...
The regresssion tool says the limit is 16 x's. I have 30.