Question

A medical researcher is conducting a study to test the effect of an anti-depression drug. At the end of the study, the researcher found that of the 4400 randomly selected subjects who took the drug 301 had no improvement at all. Of the 4700 randomly selected subjects who took the placebo 357 had no improvement at all. At can you support the claim that the proportion of subjects that have no improvement is the same for both groups.

Answer 1

sample 1: Sample number of events Sample size Sample proportion 301 Given 400 Given = 0.068409 =- sample 2 Sample number of event Sample size 357 Given 4700 Given 2 Sample proportion 0.075957 112 niP1 Pooled proportion n1 n2 Null hypothesis Alternative hypothesis 0.05 say Level of significance Two tailed Critical value a/21.96Fromztable Decision rule: Reject HO if 1.96 or z> 1.96 z< Standard error 0.005433 12 Point estimate 20.007548 Test statistic: 1.39 2 p-value: -1.39 For z= the two tailed p-value is 0.16452 Decision: Since p-value >α,do not reject HO Conclusion: There is sufficient evidence to support the claim