The SAS System

The TTEST Procedure
 
Variable: extra

group Method N Mean Std Dev Std Err Minimum Maximum
1   10 0.7500 1.7890 0.5657 -1.6000 3.7000
2   10 2.3300 2.0022 0.6332 -0.1000 5.5000
Diff (1-2) Pooled   -1.5800 1.8986 0.8491    
Diff (1-2) Satterthwaite   -1.5800   0.8491    

group Method Mean 95% CL Mean Std Dev 95% CL Std Dev
1   0.7500 -0.5298 2.0298 1.7890 1.2305 3.2660
2   2.3300 0.8977 3.7623 2.0022 1.3772 3.6553
Diff (1-2) Pooled -1.5800 -3.3639 0.2039 1.8986 1.4346 2.8077
Diff (1-2) Satterthwaite -1.5800 -3.3655 0.2055      

Method Variances DF t Value Pr > |t|
Pooled Equal 18 -1.86 0.0792
Satterthwaite Unequal 17.776 -1.86 0.0794

Equality of Variances
Method Num DF Den DF F Value Pr > F
Folded F 9 9 1.25 0.7427



The SAS System

The TTEST Procedure
 
Variable: extra

N Mean Std Dev Std Err Minimum Maximum
20 1.5400 2.0179 0.4512 -1.6000 5.5000

Mean 95% CL Mean Std Dev 95% CL Std Dev
1.5400 0.5956 2.4844 2.0179 1.5346 2.9473

DF t Value Pr > |t|
19 3.41 0.0029



The SAS System

The TTEST Procedure
 
Difference: extra_2 - extra_1

N Mean Std Dev Std Err Minimum Maximum
10 1.5800 1.2300 0.3890 0 4.6000

Mean 95% CL Mean Std Dev 95% CL Std Dev
1.5800 0.7001 2.4599 1.2300 0.8460 2.2455

DF t Value Pr > |t|
9 4.06 0.0028