The average power of a generic drug used for the common cold should be 5.0 + 0.1 mg / cc so that it can be sold in international trade compliance with government regulations related to controlled drugs. A manufacturer of this medicine claims that it produces this drug compliance with established standards. To verify this claim power four samples were taken by sampling average of four lots. The results were: 4.94, 5.09, 5.03 and 4.90 mg / cc. These results, presented sufficient evidence to indicate that the average power of this manufacturing is different from 5 mg / cc? Make a test with a = 0.05