Question

Tests for adverse reactions to a new drug yielded the results given in the table. At the 0.05 significance level, test the claim that the treatment (drug or placebo) is independent of the reaction (whether or not headaches were experienced). Round your answer to 3 decimal places. Headaches No Headaches Drug Placebo 11 7 73 91 O p-value=0.180, evidence support claim Op-value=0.906, evidence support claim Oo ooo p-value=0.180, evidence not support claim p-value=0.906, evidence not support claim O p-value=0.018, evidence not support claim

Answer 1

Ho : The treatment is independent of the reaction. Hi The treatment is dependent of the reaction L = 0.05 observed frequencies (ou). Drug placebo Headaches 7 No Headaches 91 Total 84 98 Total 18 164 182 Expected Frequencies Drug placebo Headaches 84x18 = 8.31 98X18 = 182 182 Total 9,69 18 164 No Headaches 84% 164 = 95.69 98x164 = 88.31 182 182 Total 84 98 182 test statistic x² = Ž Ž (Coig - Eij) 7 i=151

2 (11-8,31)2 8.31 + (1 -9.69)2 + C+3 -75.69)?]+[G1 - 88.3127 9.69 75.69 88.31 19 0.87 +0,75 +0.10 +0.08 x = 1.8 d. f = for 1) (C-1) - (2-1) (2-1) r = no. of rows c = no. of columns d of P-value = P(xå.f>x²) = P(x² > 1.8) = 1- POx<1-8) = -0.8203 = 0.1797 praline 20.180 Decision Reject Ho if p-value <a Here Prele = 0.180 > 220.05 Fail to reject Ho, Pvale = 0.180 evidence support claim.