An experiment was conducted to test the efficacy of chloromycetin in checking typhoid. In a certain hospital chloromycetin was given to 285 out of the 392 patients suffering from typhoid. The number of typhoid cases were as follows: Typhoid No Typhoid Total Chloromycetin 35 250 285 No chloromycetin 50 57 107 Total 85 307 392 With the help of x2 , test the effectiveness of chloromycetin in checking typhoid. (The x2 value at 5 per cent level of significance for one degree of freedom is 3.841).