will find the expected count for the cell in row 1 and column 1. The proportion of Observed versus expected counts all 72 subjects who succeed in avoiding a count of successes column I total 24 Yes table total table total 72 3 D 16 Think of this as p, the overall proportion of 16 successes. If H is true, we expect this same proportion of successes in all three groups Because 1/3 of all subjects succeed, we So the expected count of successes among the 24 subjects who took D is expect 1/3 of the 24 subjects in each group to avoid a relapse if there are no differences among the treatments. In fact, D has more successes(14)and fewer failures(10)than expected. The Phas fewer successes (4)and more relapses This expected count has the form (20). d does much better than P, with L in row I total× column l total24×24 table total 7211 21 • We will find the expected count for the cell in row 1 and column 1. The proportion of all 72 subjects who succeed in avoiding a relapse is count of successes column 1 total 24 1 table total table total 72 3 = == Think of this as p, the overall proportion of successes. If is true, we expect this same proportion of successes in all three groups. H0 22 • So the expected count of successes among the 24 subjects who took D is 1 24 8 3 np = ×= This expected count has the form: row 1 total column 1 total 24 24 table total 72 × × = 12 23 Observed versus expected counts 24 • Because 1/3 of all subjects succeed, we expect 1/3 of the 24 subjects in each group to avoid a relapse if there are no differences among the treatments. In fact, D has more successes (14) and fewer failures (10) than expected. The P has fewer successes (4) and more relapses (20). D does much better than P, with L in between