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          Abstract: | 
           
              Given the positive real numbers   and  , let  ,  , and   denote their arithmetic mean, geometric mean, and identric mean, respectively. It is proved that for  , the double inequality     holds true for all positive real numbers   if and only if    and   . This result complements a similar one established by H. Alzer and S.-L. Qiu [Inequalities for means in two variables, Arch. Math. (Basel) 80 (2003), 201-215]. 
            
          
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