19. An expei7Iment was conducted to test the effect of four different drugs on blood coagulation time (in minutes). Specimens of blood drawn from 10 subjects were divided equally into four parts that were randomly assigned to one of the four drugs. The results were as follows:

Subject Drug W X A 1.5 1.8 1.7 1.9 B 1.4 1.4 1.3 1.5 C 1.8 1.6 1.5 1.9 D 1.3 1.2 1.2 1.4 E 2.0 2.1 2.2 2.3 F 1.1 1.0 1.0 1.2 G 1.5 1.6 1.5 1.7 H 1.5 1.5 1.5 1.7 I 1.2 1.0 1.3 1.5 J 1.5 1.6 1.6 1.9 Can we conclude on the basis of these data that the drugs have different effects? Let a = .05.