An article describes a study of the effectiveness of a fabric device that acts like a support stocking for a weak or damaged heart. In the study, 88 people who consented to treatment were assigned at random to either a standard treatment consisting of drugs or the experimental treatment that consisted of drugs plus surgery to install the stocking. After two years, 32% of the 41 patients receiving the stocking had improved, while 24% of the patients receiving the standard treatment had improved. Do these data provide evidence that the proportion of patients who improve is significantly higher for the experimental treatment than for the standard treatment? After checking to make sure that all of the necessary conditions were met, we calculated the value of the z test statistic to be z = 0.84. Which of the following is the P-value associated with this test?
A)0
B)0.20
C)0.41
D)0.10
E)0.01

Question

Quizplus · Accepted Answer

Given the z test statistic of 0.84, the P-value associated with this test is closest to 0.20. This is because the P-value represents the probability of observing a test statistic as extreme as, or more extreme than, the observed value under the null hypothesis. A z score of 0.84 corresponds to a P-value around 0.20 in a two-tailed test, indicating that the evidence is not strong enough to reject the null hypothesis at common significance levels (e.g., 0.05).

An Article Describes a Study of the Effectiveness of a Fabric