Confidence interval for the regression fit

[AnaG_]

Hello,
When using proc reg for example with clm option, in the graph, there is a gray zone arround the regression line indicating the confidence interval of the fit (the dependent variable expected mean). It looks like a very wide hyperbola around the regression line. How do I find the formula for its limits? What is the formula SAS uses to calculate the CI for the mean when the clm option is applied? I couldn't find anything in the documentation. Thank you for the help.

[StatDave]

See the "Statistical Background in Linear Regression" section in the Introduction to Regression Procedures chapter of the SAS/STAT User's Guide. Formulas are shown in the subsections.

[AnaG_]

Thank you very much for the help.

[Laser_Taco_ · Accepted solution]

Hi there @AnaG_ , 

Here is a link to the formulas in the documentation, and here  is a link to the formulas themselves. 

Follows the standard calculation for CI found in statistics textbooks.

Regards, 

Kyle