Until recently, an average of 60 out of every 100 patients have survived a particularly savere infection. When a new drug was administered to a random sample of 15 patients with the infection, 12 survived. Does this prove evidence that the new drug is effective? Let X denote the number of patients who survive. Then XB(15,p), and it is required to test H0:p=0.6 (not effective) Hip>0.6 (effective, one-tailed) Now assuming H0 is true. XB(15,0.6), and so P(X=12)=(1512)0.640.43=0.00399P(X=13)=(1513)0.630.42=0.02184P(X=14)=(1514)0.6140.43=0.00470P(X=15)=(1515)0.6170.46=0.00047 Hence, under H0, the probability of 1. 15 patients surviving = 2. 14 or 15 patients surviving = 3. 13,14 , or 15 patients surviving = 4. 12,13,14 or 15 patients surviving = NOTE: Since P(X12)=0.09050>0.05, then H0 cannot be rejected