Concept explainers
Angioplasty’s benefits challenged. More than 1 million heart patients each year undergo an angioplasty. The benefits of an angioplasty were challenged in a study of 2,287 patients (2007 Annual Conference of the American College of Cardiology. New Orleans). All the patients had substantial blockage of the arteries but were medically stable. All were treated with medication such as aspirin and beta-blockers However, half the patients were randomly assigned to get an angioplasty and half were not After 5 years, the researchers found that 211 of the 1,145 patients in the angioplasty group had subsequent heart attacks compared with 202 of 1,142 patients in the medication-only group Do you agree with the study’s conclusion. “There was no significant difference in the rate of heart attacks for the two groups”? Support your answer with a 95% confidence interval.
Want to see the full answer?
Check out a sample textbook solutionChapter 8 Solutions
Statistics for Business and Economics (13th Edition)
- What is an experiment?arrow_forwardWhat is meant by the sample space of an experiment?arrow_forwardAngioplasty's benefits challenged. More than 1 million heart patients each year undergo an angioplasty. The ben- efits of an angioplasty were challenged in a study of 2,287 patients (2007 Annual Conference of the American College of Cardiology, New Orleans). All the patients had substantial blockage of the arteries but were medically stable. All were treated with medication such as aspirin and beta-blockers. However, half the patients were ran- domly assigned to get an angioplasty and half were not. After 5 years, the researchers found that 211 of the 1,145 patients in the angioplasty group had subsequent heart attacks compared with 202 of 1,142 patients in the medica- tion-only group. Do you agree with the study's conclusion, "There was no significant difference in the rate of heart attacks for the two groups"? Support your answer with a 95% confidence interval.arrow_forward
- A psychologist conducts a 2 x 3 x 2 ANOVA. How many main effects are possible? How many interactions are possible?arrow_forwardAlthough arsenic is known to be a poison, it also has some beneficial medicinal uses. In one study of the use of arsenic to treat acute promyelocytic leukemia (APL), a rare type if blood cancer, APL patients were given an arsenic compound as part of their treatment. Of those receiving arsenic, 32% were in remission and showed no signs of leukemia in subsequent examination. It is known that 18% of APL patients go into remission after conventional treatment. Suppose that the study had included 100 randomly selected patients. Is there sufficient evidence to conclude that the proportion in remission for the arsenic treatment is greater than 0.18, the remission proportion for conventional treatment? a. Test the hypothesis at the 0.01 significance level. b. Construct and interpret a 99% confidence interval for the true proportion of APL patients who go into remission after using arsenic. Does the inference drawn from this interval match the conclusion from the test that you did in part…arrow_forwardYou are concerned that nausea may be a side effect of Tamiflu, but you cannot just give Tamiflu to patients with the flu and say that nausea is a side effect if people become nauseous. This is because nausea is common for people who have the flu. From past studies you know that about 32% of people who get the flu experience nausea. You collected data on 2254 patients who were taking Tamiflu to relieve symtoms of the flu, and found that 778 experienced nausea. Use a 0.01 significance level to test the claim that the percentage of people who take Tamiflu for the relief of flu symtoms and experience nausea is greater than 32%.a) Identify the null and alternative hypotheses?H0H0: ? p = p ≠ p < p > p ≤ p ≥ μ = μ ≠ μ < μ > μ ≤ μ ≥ H1H1: ? p = p ≠ p < p > p ≤ p ≥ μ = μ ≠ μ < μ > μ ≤ μ ≥ b) What type of hypothesis test should you conduct (left-, right-, or two-tailed)? left-tailed right-tailed two-tailed c) Identify the appropriate significance level.d) Calculate…arrow_forward
- You are concerned that nausea may be a side effect of Tamiflu, but you cannot just give Tamiflu to patients with the flu and say that nausea is a side effect if people become nauseous. This is because nausea is common for people who have the flu. From past studies you know that about 32% of people who get the flu experience nausea. You collected data on 2254 patients who were taking Tamiflu to relieve symtoms of the flu, and found that 778 experienced nausea. Use a 0.01 significance level to test the claim that the percentage of people who take Tamiflu for the relief of flu symtoms and experience nausea is greater than 32%. d) Calculate your test statistic. Write the result below, and be sure to round your final answer to two decimal places.e) Calculate your p-value. Write the result below, and be sure to round your final answer to four decimal places.f) Do you reject the null hypothesis? We reject the null hypothesis, since the p-value is less than the significance level. We…arrow_forwardA health officer thinks that there is an association between diabetes (DM) and hypertension (HPT). He believes that those with DM are more likely to have HPT as well. For his research, from the hospital records, he selected a random sample of 400 patients, 300 with DM and 100 without DM. Out of the 300 DM patients, 60 had HPT as well and out of the 100 non DM patients 10 had HPT. He also recorded the patients’ gender. With the data, he performed two analyses, one for all policyholders and the other by gender. The following are some of the output from SPSS. Must the manager consider gender as well in this case? If yes, stating the evidence, explain why. If you are the health officer, how would the results above help you in making decision? What other variables, if any, should be considered as well?arrow_forwardA health officer thinks that there is an association between diabetes (DM) and hypertension (HPT). He believes that those with DM are more likely to have HPT as well. For his research, from the hospital records, he selected a random sample of 400 patients, 300 with DM and 100 without DM. Out of the 300 DM patients, 60 had HPT as well and out of the 100 non DM patients 10 had HPT. He also recorded the patients’ gender. With the data, he performed two analyses, one for all policyholders and the other by gender. The following are some of the output from SPSS. State the percentage of DM and non DM patients who had State the test that was used in these Test if there is an association between DM and HPTarrow_forward
- Outline the components of the classical experimental design. How is it different from a one-group pre-test post-test design?arrow_forwardresearcher suspects that the actual prevalence of generalized anxiety among children and adolescents is higher than the previously reported prevalence of generalized anxiety disorder among children and adolescents. The previously reported prevalence of generalized anxiety disorder among children and adolescents is 3.9%, and the researcher conducts a study to test the accuracy of the previously reported prevalence of generalized anxiety disorder by recruiting 98 children and adolescents from various pediatricians' offices and tests them for generalized anxiety disorder using the DSM-5. The researcher determines that the prevalence of generalized anxiety disorder among the participants of the study is 6.1%. What should the researcher's conclusion be for a 5% significance level? A. We reject H0 at the 5% level because -57.53 is less than -1.96. We do have statistically significant evidence to show the actual prevalence of generalized anxiety disorder among children and adolescents…arrow_forwardYou are reviewing data on a clinical trial of 50-70-year-olds, on the effects of a vitamin supplement on arthritis. In the general population for this age range, 35% of the people have some arthritis symptoms. In the clinical trial of 500 people, they find that 170 have some arthritis symptoms. What do you conclude about the efficacy of the vitamin supplement? (Show relevant work)arrow_forward
- Calculus For The Life SciencesCalculusISBN:9780321964038Author:GREENWELL, Raymond N., RITCHEY, Nathan P., Lial, Margaret L.Publisher:Pearson Addison Wesley,Big Ideas Math A Bridge To Success Algebra 1: Stu...AlgebraISBN:9781680331141Author:HOUGHTON MIFFLIN HARCOURTPublisher:Houghton Mifflin HarcourtCollege Algebra (MindTap Course List)AlgebraISBN:9781305652231Author:R. David Gustafson, Jeff HughesPublisher:Cengage Learning