The Diabetes Prevention Study was a randomized study conducted in Finland in which middle-aged participants (
Table 8.30 Mean weight change by treatment group among people with IGT in the Diabetes Prevention Study
*Follow-up weight – baseline weight.
For the purposes of this problem, for any degrees of freedom (d) ≥ 200, assume that td ≅ N (0, 1) distribution.
What test can be used to assess mean changes in weight in the intervention group?
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Fundamentals of Biostatistics
- The article “Treadmill Exercise and Resistance Training in Patients With Peripheral Arterial Disease With and Without Intermittent Claudication. A Randomized Controlled Trial” (M. McDermott, P. Ades, et al., Journal of the American Medical Association, 2009:165–174) reported the results of a study to determine whether treadmill exercise could improve the walking ability of patients suffering from claudication, which is pain caused by insufficient blood flow to the muscles of the legs. A sample of 48 patients walked on a treadmill for six minutes every day. After six months, the mean distance walked in six minutes was 348 m, with a standard deviation of 80 m. For a control group of 46 patients who did not walk on a treadmill, the mean distance was 309 m with a standard deviation of 89 m. Find a 95% confidence interval for the difference in mean distance walked between the two groups of patients.arrow_forwardThe article “Treadmill Exercise and Resistance Training in Patients With Peripheral Arterial Disease With and Without Intermittent Claudication. A Randomized Controlled Trial” (M. McDermott, P. Ades, et al., Journal of the American Medical Association, 2009:165–174) reported the results of a study to determine whether treadmill exercise could improve the walking ability of patients suffering from claudication, which is pain caused by insufficient blood flow to the muscles of the legs. A sample of 48 patients walked on a treadmill for six minutes every day. After six months, the mean distance walked in six minutes was 348 meters, with a standard deviation of 80 m. For a control group of 46 patients who did not walk on a treadmill, the mean distance was 309 m with a standard deviation of 89 m. Can you conclude that the mean distance walked for patients using a treadmill is greater than the mean for the controls? Use the α = 0.05 level of significance.arrow_forwardIn randomized, double-blind clinical trials of a new vaccine, children were randomly divided into two groups. Subjects in group 1 received the new vaccine while subjects in group 2 received a control vaccine. After the second dose, 116 of 651 subjects in the experimental group (group 1) experienced fever as a side effect. After the second dose, 73 of 532 of the subjects in the control group (group 2) experienced fever as a side effect. Does the evidence suggest that a higher proportion of subjects in group 1 experienced fever as a side effect than subjects in group 2 at the α=0.10 level of significance? #1 Find the test statistic for this hypothesis test.arrow_forward
- In randomized, double-blind clinical trials of a new vaccine, infants were randomly divided into two groups. Subjects in group 1 received the new vaccine while subjects in group 2 received a control vaccine. After the second dose, 126 of 387 subjects in the experimental group (group 1) experienced drowsiness as a side effect. After the second dose, 158 of 574 of the subjects in the control group (group 2) experienced drowsiness as a side effect. Does the evidence suggest that a higher proportion of subjects in group 1 experienced drowsiness as a side effect than subjects in group 2 at the α=0.01 level of significance? Verify the model requirements. Select all that apply. A. The sample size is less than 5% of the population size for each sample. B. n1p11−p1≥10 and n2p21−p2≥10 C. The samples are dependent. D. The sample size is more than 5% of the population size for each sample. E. The samples are independent. F. The data come…arrow_forwardElizon Pharmaceuticals, Inc., announced the results of its first human trial of NPI 32101, a topical form of its skin ointment. A total of 225 patients diagnosed with skin irritations were randomly divided into three groups as part of a double-blind, placebo-controlled study to test the effectiveness of the new topical cream. The first group received a 0.5% cream, the second group received a 1.0% cream, and the third group received a placebo. Groups were treated twice daily for a 6-week period. (a)What type of experimental design is this? (b)What is the control group for this study? (c)What is the factor that is set to predetermined levels? What is the treatment? (d)What does it mean for this study to be double-blind? (e)Identify the experimental units. (f)Draw a diagram to illustrate the design.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
- A 2017 article in The New England Journal of Medicine details the results of a randomized clinical trial designed to evaluate the efficacy of a rotavirus gastroenteritis vaccine designed for infants. As per the authors: “Each year, rotavirus gastroenteritis is responsible for about 37% of deaths from diarrhea among children younger than 5 years of age worldwide, with a disproportionate effect in sub-Saharan Africa. We conducted a randomized, placebo-controlled trial in Niger to evaluate the efficacy of a live, oral bovine rotavirus pentavalent vaccine (BRV-PV, Serum Institute of India) to prevent severe rotavirus gastroenteritis. Healthy infants received three doses of the vaccine or placebo at 6, 10, and 14 weeks of age. Episodes of rotavirus gastroenteritis were assessed through active and passive surveillance.” The following Kaplan-Meier curves show the time to a diagnosis of rotavirus gastroenteritis separately for the vaccine and placebo samples. Infants were followed for up to 60…arrow_forwardThe Joint Commission on Accreditation of Healthcare Organizations mandated that hospitals ban smoking by 1994. To study the effects of this ban on smoking behaviors, subjects were randomly selected from two different populations: those from hospitals with the ban and those from hospitals without the ban. Investigators were interested in determining if this smoking ban had any impact on the proportion of smokers employed at each hospital that then quit smoking. Let px be the proportion of smokers from hospitals that implemented the ban who quit smoking during the study period. Let py be the proportions of smokers from hospitals without the ban who quit smoking during the study period. Please select the appropriate hypotheses. H0: px = 0.50 HA: px ≠ 0.50 H0: px-py ≥ 0 HA: px-py H0: px-py ≤ 0 HA: px-py > 0 H0: px-py = 0 HA: px-py ≠ 0arrow_forwardIn a study conducted in the Science Department of Faculty of Science, Technology and Human Development in a University; the researcher examined the influence of the drug succinylcholine on the circulation levels of androgens in the blood. Blood samples from wild, free-ranging deer were obtained via the jugular vein immediately after an intramuscular injection of succinylcholine using darts and a capture gun. Deer were bled again approximately 30 minutes after the injection and then released. The level of androgens at time of capture and 30 minutes later, measured in nanograms per milliliter (ng/ml), for 15 deers as in Table Q1. Assuming that the populations of androgen at time of injection and 30 minutes later are normally distributed:i) Find the average and standard deviation of this studyii)Determine the critical region of this problem.iii) Test at the 0.05 level of significance whether the androgen concentrations are altered after 30 minutes of restraint.arrow_forward
- A hospital conducted a study of the waiting time in its -emergency room. The hospital has a main campus and three -satellite locations. Management had a business objective of reducing waiting time for emergency room cases that did not require immediate attention. To study this, a random sample of 15 emergency room cases that did not require immediate attention at each location were selected on a particular day, and the waiting times (measured from check- in to when the patient was called into the clinic area) were collected and stored in the table. a) At the 0.05 level of significance, is there evidence of a difference in the mean waiting times in the four locations? Main Satellite 1 Satellite 2 Satellite 3 120.08 30.75 75.86 54.05 81.90 61.83 37.88 38.82 78.79 26.40 68.73 36.85 63.83 53.84 51.08 32.83 79.77 72.30 50.21 52.94 47.94 53.09 58.47 34.13 79.88 27.67 86.29 69.37 48.63 52.46 62.90 78.52 55.43 10.64 44.84 55.95 64.06 53.50 64.17 49.61 64.99 37.28…arrow_forwardA consumer advocacy group wanted to study whether different airline carriers differed in terms of their delayed flights. In particular, the researchers were interested in the relationship between p1, the proportion of Alpha Airlines flights that were delayed at least 15 minutes, and p2, the proportion of Beta Airlines flights that were delayed at least 15 minutes. A random sample of 1,000 Alpha flights and a separate random sample of 1,000 Beta flights found that 67 of the Alpha fights and 160 of the Beta flights were delayed at least 15 minutes. The conditions for inference were checked and verified. Does this set of samples provide strong evidence that Alpha Airlines has a smaller proportion of flights that are delayed at least 15 minutes than Beta Airlines, at the α = 0.05 significance level? Find the z-table here. A. The test statistic is z = –6.56 and the P-value ≈ 0. Since the P-value ≈ 0 < 0.05, there is not sufficient evidence that Alpha Airlines has fewer delayed…arrow_forwardThe researchers sought to explore the connection between dietary fat consumption and the incidence of cardiovascular disease (CVD) events in a cohort of 5,115 young adults of both Black and White backgrounds. In 1985, these individuals underwent an initial examination. Over the subsequent 35 years, those who were initially free of disease were monitored to investigate the potential associations between their dietary fat intake and the occurrence of CVD events. Among the 2,100 young adults who had a high-fat diet at the start of the study, 255 experienced a new CVD event. Among the 3,015 young adults who did not have a high-fat diet at baseline, 125 experienced a new CVD event during the follow-up period. Risk of CVD events among those with a high-fat diet is ____. Risk of CVD events among those without a high-fat is ____. The relative risk is ____.arrow_forward
- Holt Mcdougal Larson Pre-algebra: Student Edition...AlgebraISBN:9780547587776Author:HOLT MCDOUGALPublisher:HOLT MCDOUGAL