Hi I am a learner who is trying to build my first stats model which is aiming at winning chance prediction for business quotes.

The stats model I use is the logistic regression. after going through the variable selection process it finally contains 4 categorical variables plus 2 numeric variables. the tool we got here is sas 9.3.

My latest issue is regards to the estimated probability ratios produced in sas output.

It seems I can't replicate the probability calculation correctly as long as the omitted dummy variable is involved (in this case, I suspect acg=3 is causing the problem.) All the details are available on the attached spreadsheet. I have highlighted the those matched estimated probability in green; otherwise in red. Hope this would be a simple problem due to my misunderstanding. will appreciate for any suggestions which might help.

Thanks!

The stats model I use is the logistic regression. after going through the variable selection process it finally contains 4 categorical variables plus 2 numeric variables. the tool we got here is sas 9.3.

My latest issue is regards to the estimated probability ratios produced in sas output.

It seems I can't replicate the probability calculation correctly as long as the omitted dummy variable is involved (in this case, I suspect acg=3 is causing the problem.) All the details are available on the attached spreadsheet. I have highlighted the those matched estimated probability in green; otherwise in red. Hope this would be a simple problem due to my misunderstanding. will appreciate for any suggestions which might help.

Thanks!

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