The below text is from a practice exam, which has the answer of interest. I am having a lot of difficulty understanding how to arrive at that result, if anyone can provide the process by which z=-460.83, I would greatly appreciate it.
A large study was conducted to test the effectiveness of an experimental blood thinner, clopidogrel, in warding off heart attacks and strokes. The study involved 19,185 patients who had suffered heart attacks, strokes, or pain from clogged arteries. They were each randomly assigned to take either aspirin or clopidogrel for a period of 1 to 3 years. Of the patients taking aspirin, 5.3% suffered heart attacks, strokes, or death from cardiovascular disease; the corresponding percentage in the clopidogrel patients was 5.8%.
Answer: b. yes, z=-460.83
A large study was conducted to test the effectiveness of an experimental blood thinner, clopidogrel, in warding off heart attacks and strokes. The study involved 19,185 patients who had suffered heart attacks, strokes, or pain from clogged arteries. They were each randomly assigned to take either aspirin or clopidogrel for a period of 1 to 3 years. Of the patients taking aspirin, 5.3% suffered heart attacks, strokes, or death from cardiovascular disease; the corresponding percentage in the clopidogrel patients was 5.8%.
- The article states that each patient was randomly assigned to one of the two medications. Explain how you could use the random number table to make these assignments.
- Although the article does not give the sample sizes, assume that the randomization in part (a) results in 9925 aspirin and 9260 clopidogrel assignments. Are the results of the study statistically significant? Use the appropriate test of hypothesis.
- What do the results of the study mean in terms of their practical importance?
Answer: b. yes, z=-460.83