Data - Best Subsets
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Enter response and predictor variables in the worksheet in numeric columns of equal length so that each row in your worksheet contains measurements on one unit or subject. Minitab automatically omits rows with missing values from all models.

You can use as many as 31 free predictors. However, the analysis can take a long time when 15 or more free predictors are used. When analyzing a very large data set, forcing certain predictors to be in the model by entering them in Predictors in all models can decrease the length of time required to run the analysis. The total number of predictors (forced and free) in the analysis can not be more than 100.