/*-----------------------------------------------------------------
            S A S   S A M P L E   L I B R A R Y                   
                                                                  
      NAME: pwrgs2                                                
     TITLE: Getting Started Example 2 for PROC POWER              
            (Determining Required Sample Size for a Two-Sample    
            t Test)                                               
   PRODUCT: STAT                                                  
    SYSTEM: ALL                                                   
      KEYS: power                                                 
            power analysis                                        
     PROCS: POWER                                                 
      DATA:                                                       
                                                                  
   SUPPORT: John Castelloe                                        
       REF:                                                       
      MISC:                                                       
-----------------------------------------------------------------*/

proc power;
   twosamplemeans
      groupmeans   = (13 14) (13 14.5) (13 15)
      stddev       = 1.2 1.7
      groupweights = 1 | 1 2 3
      power        = 0.9
      ntotal       = .;
run;

proc power;
   twosamplemeans
      nfractional
      meandiff     = 1 to 2 by 0.5
      stddev       = 1.2 1.7
      groupweights = (1 1) (1 2) (1 3)
      power        = 0.9
      ntotal       = .;
run;