Question

a. Please state both the null and alternative hypotheses for this question. b. Provide the decision rule for making this decision. Use an alpha level of .05. c. Show all the work necessary to calculate the appropriate statistic. d. What conclusion are you allowed to draw? Write a conclusions sentence in APA format (i.e., it includes the appropriate statistical information).

In a study of the effectiveness of an antipsychotic drug, patients treated with the drug were compared to patients receiving a placebo. In terms of the number relapsing, 698 of 1,068 patients relapsed after taking the placebo while 639 out of 2,127 patients relapsed after taking the antipsychotic drug. Test the prediction that the antipsychotic is significantly more effective in preventing relapse than the placebo.

Answer 1

Sample 1, Placebo test:

x1 = 698, n1 = 1068

= 0.6536

Sample 2, Anti-psychotic drug:

x2= 639, n2 = 2127

= 0.3004

Pooled proportion =

a) Null and alternative hypothesis:

Ho: p1 = p_2

Ha: p1 < p2

b) Decision rule:

if p-value > , do not reject the null hypothesis. otherwise reject it.

c) Test statistic:

p-value = NORM.S.DIST(19.0878,TRUE) = 1

d) Conclusion:

As p = 1 >0.05, we fail to reject the null hypothesis.

there is not enough evidence to claim that antipsychotic is significantly more effective in preventing relapse than the placebo at 0.05 significance level.