Commonly used vaccines for influenza are trivalent and contain only one type of influenza B virus. They may be ineffective against other types of influenza B virus. A randomized clinical trial was performed among children 3 to 8 years of age in 8 countries. Children received either a quadrivalent vaccine (QIV) that had more than one influenza B virus or a trivalent Hepatitis A vaccine (control) (Jain, et al., [9]. New England Journal of Medicine 2013: 369(26): 2481–2491). An attack rate (i.e.,% of children who developed influenza) starting 14 days after vaccination until the end of the study was computed for each vaccine group, stratified by age. The following data were reported:
Table 3.7 Attack rate for influenza by age and treatment group
Suppose 3 children in a village ages 3, 5, and 7 are vaccinated with the QIV vaccine. What is the
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Chapter 3 Solutions
Fundamentals of Biostatistics
- What is meant by the sample space of an experiment?arrow_forwardSickle-cell anemia is hereditary medical condition that affects red blood cells and is thought to protect against malaria, a debilitating parasitic infection of the liver and blood. That would explain why the sicklo-cell trait is found in people who originally came from Africa, where malaria is widespread . A landmark study in Africa tested children for the sickle-cell trait and also for malarin infection In all, 25% of the children had the sickle-cell trait, and 6.6% of the children had both the sickle-cell trait and malaria . Overall, 34.6% of the children had malaria. What is the probability that a child has the sickle-cell trait , given that the child doesn't have malaria?arrow_forwardA researcher studied iron-deficiency anemia in women in each of two developing countries. Differences in the dietary habits between the two countries led the researcher to believe that anemia is less prevalent anong women in the first country than among women in the second country. A random sample of 2000 women from the first country yielded 488 women with anemia, and an independently chosen, random sample of 1700 women from the second country yielded 437 women with anemia. Based on the study can we conclude, at the 0.05 level of significance, that the proportion p, of women with anemia in the first country is less than the proportion p, of women with anemia in the second country? Perform a one-tailed test. Then complete the parts below. Carry your intermediate computations to three or more decimal places and round your answers as specified in the parts below. (If necessary, consult a list of formulas.) (a) State the null hypothesis H, and the alternative hypothesis H,. H : p1 = 2 H,…arrow_forward
- In a study conducted by the U.S. Department of Health and Human Services, a sample of 546 boys aged 6–11 was weighed, and it was determined that 87 of them were overweight. A sample of 508 girls aged 6–11 was also weighed, and 74 of them were overweight. Can you conclude that the proportion of boys who are overweight differs from the proportion of girls who are overweight? Please show calcularrow_forwardA clinical trial is run among 40 HIV patients in order to assess the effectiveness of a new anti-retroviral therapy. Patients are randomized. One group received the standard anti-retroviral therapy (usual care) while the other group received the new anti-retroviral therapy. They are monitored for three months. The primary variable is the viral load which represents the number of HIV copies per milliliter of blood. The most appropriate statistical test to determine the significant difference in viral load in patients receiving the standard versus the new anti-retroviral therapy is Mann- Whitney U Test. a.True b.Falsearrow_forwardA pathological video game user (PVGU) is a video game user that averages 31 or more hours a week of gameplay. According to the article “Pathological Video Game Use among Youths: A Two-Year Longitudinal Study” (Pediatrics, Vol. 127, No. 2, pp. 319–329) by D. Gentile et al., in 2011, about 9% of children in grades 3–8 were PVGUs. Suppose that, today, five youths in grades 3–8 are randomly selected. Let X represent the number of youths who are PVGUs. n = p = 1 – p = Prepare the probability distribution for the random variable X. Complete the following table. Round your answers to 4 decimal places e.g. 0.XXXX or .XXXX. X = x P(X=x) 0 1 2 3 4 5 ∑=1.0000∑=1.0000 Calculate the probability that EXACTLY three youths are PVGUs. Round your answers to 4 decimal places e.g. 0.XXXX or .XXXX. P(X = 3) = Calculate the probability that AT LEAST two youths are PVGUs. Round your answers to 4 decimal places e.g. 0.XXXX or .XXXX. P(X ≥ 2) = Calculate the…arrow_forward
- Treatment of patients whose injuries might cause massive blood loss has involved giving them plasma transfusions after they had been admitted to the emergency room. Sperry et al. (2018) investigated whether earlier treatment by the first responder might be more effective. In a randomized control trial, patients with trauma either did or did not receive earlier plasma transfusion. Of the 220 patients who received early plasma treatment, 52 died while of the 261 who received standard care, 89 died. Does the earlier treatment of plasma transfusion seem to be more effective? Standard Treatment 89 Early Treatment Died 52 Survived 167 173 What analysis is appropriate to run? heteroscedastic t-test Opaired t-test odds ratio O chi-squared goodness of fit homoscedastic t-testarrow_forwardGinkgo for Dementia. The herb ginkgo biloba is commonly used as a treatment to prevent dementia. In a study of the effectiveness of this treatment, 1545 elderly subjects were given ginkgo and 1524 elderly subjects were given a placebo. those in the ginkgo group, 246 later developed dementia, and among those in the placebo group, 277 later developed dementia ( based on data from " Ginkgo Biloba for Prevention of Dementia," by DeKosky et al., Journal of the American Medical Association, Vol. 300No. 19). We want to use a 0.01 significance level to test the claim that ginkgo is effective in preventing dementia.arrow_forwardIn a randomized double-blind clinical trials of a new vaccine children were randomly divided into two groups subjects in group one received the new vaccine while subjects in group 2 received a control vaccine after the second dose 112 of 690 subjects in the experimental group 1 experienced drowsiness as a side effect after the second dose 69 of 571 of the subjects in the control group 2 experienced drowsiness as a side effect does the evidence suggest that a higher proportion of subjects in group 1 experience drowsiness as a side effect than subjects in group 2 at 0.05 level of significance? Determine the null and alternative hypothesis? find the test statistic for this hypothesis test? determine the P value for this hypothesis test? do we reject or not reject the null hypothesis and why? State your conclusion?arrow_forward
- The Paleo diet allows only for foods that humans typically consumed over the last 2.5 million years, excluding those agriculture-type foods that arose during the last 10,000 years or so. Researchers randomly divided 500 volunteers into two equal-sized groups. One group spent 6 months on the Paleo diet. The other group received a pamphlet about controlling portion sizes. A randomized treatment assignment was performed, and at the beginning of the study, the average difference in weights between the two groups was about 0 pounds. After the study, the Paleo group had lost an average of 7.1 pounds with a standard deviation of 22.75 pounds while the control group had lost an average of 4.5 pounds with a standard deviation of 11.5 pounds. After failing to reject the null hypothesis support your answer with a p-value (a) P-value = _______arrow_forwardThe Paleo diet allows only for foods that humans typically consumed over the last 2.5 million years, excluding those agriculture-type foods that arose during the last 10,000 years or so. Researchers randomly divided 500 volunteers into two equal-sized groups. One group spent 6 months on the Paleo diet. The other group received a pamphlet about controlling portion sizes. A randomized treatment assignment was performed, and at the beginning of the study, the average difference in weights between the two groups was about 0 pounds. After the study, the Paleo group had lost an average of 6.5 pounds with a standard deviation of 22.75 pounds while the control group had lost an average of 5.2 pounds with a standard deviation of 10.25 pounds. 95% Confidence Interval ( -1.808, 4.408 ) What is the P-Value? _______arrow_forwardThe Paleo diet allows only for foods that humans typically consumed over the last 2.5 million years, excluding those agriculture-type foods that arose during the last 10,000 years or so. Researchers randomly divided 500 volunteers into two equal-sized groups. One group spent 6 months on the Paleo diet. The other group received a pamphlet about controlling portion sizes. Randomized treatment assignment was performed, and at the beginning of the study, the average difference in weights between the two groups was about 0 pounds. After the study, the Paleo group had lost an average of 7.6 pounds with a standard deviation of 20.75 pounds while the control group had lost an average of 5.8 pounds with a standard deviation of 12.5 pounds. What is the P value?arrow_forward
- College Algebra (MindTap Course List)AlgebraISBN:9781305652231Author:R. David Gustafson, Jeff HughesPublisher:Cengage Learning