Teen Court is a juvenile diversion program designed to circumvent the formal processing of first-time juvenile offenders within the juvenile justice system. The article “An Experimental Evaluation of Teen Courts” (J. of Experimental Criminology, 2008: 137–163) reported on a study in which offenders were randomly assigned either to Teen Court or to the traditional Department of Juvenile Services method of processing. Of the 56 TC individuals, 18 subsequently recidivated (look it up!) during the 18-month follow-up period, whereas 12 of the 51 DJS individuals did so. Does the data suggest that the true proportion of TC individuals who recidivate during the specified follow-up period differs from the proportion of DJS individuals who do so? State and test the relevant hypotheses using a significance level of .10.
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Chapter 9 Solutions
Student Solutions Manual for Devore's Probability and Statistics for Engineering and the Sciences, 9th
- What is meant by the sample space of an experiment?arrow_forwardWhat is an experiment?arrow_forwardWhirling disease is a deadly disease that affects trout in Montana riversIn a follow-up to a 2006 study conducted by the Montana Department of FishWildlife and Parks (FWP)researchers sought to determine if the proportion of trout afflicted by whirling disease in the Gallatin river differs between rainbow trout and brown trout. To test this theory, researchers collected a representative sample of 527 rainbow trout and 459 brown trout. Of the 527 rainbow trout collected, 120 had developed whirling disease; of the 459 brown trout collected, 74 had developed whirling disease Calculate the relative risk of whirling disease for rainbow trout compared to brown trout in this sample.arrow_forward
- Many people take ginkgo supplements advertised to improve memory. Are these over-the-counter supplements effective? In a study reported in the paper “Ginkgo for memory Enhancement” (Journal of the American Medical Association), elderly adults were assigned at random to either a treatment or a control group. The 104 participants who were assigned to the treatment group took 40 mg of ginkgo three times a day for six weeks. The 115 participants assigned to the control group took a placebo pill three times a day for six weeks. At the end of six weeks, the Wechsler Memory Scale (a test of short-term memory) was administered. Higher scores indicate better memory function. Summary values are given in the following table. TABLE ATTACHED AS PICTURE Based on these results, we want to find whether there is evidence that taking 40 mg of ginkgo three times a day is effective in increasing mean performance on the Wechsler Memory Scale. A) Calculate the test statistic for the test above. (round test…arrow_forwardIn 2002 the Supreme Court ruled that schools could require random drug tests of students participating in competitive after-school activities such as athletics. Does drug testing reduce use of illegal drugs? A study compared two similar high schools in Oregon. Wahtonka High School tested athletes at random and Warrenton High School did not. In a confidential survey, 5 of 140 athletes at Wahtonka and 26 of 143 athletes at Warrenton said they were using drugs. Regard these athletes as SRSs from the populations of athletes at similar schools with and without drug testing. Wahtonka sample size: 142 Wahtonka drug users: 6 Warrenton sample size: 145 Warrenton drug users: 27(c) Give the plus four 96% confidence interval for the difference between the proportion of athletes using drugs at schools with and without testing. Interval:arrow_forwardThe authors of the paper "Playing by the Rules: Parental Mediation of Video Game Play"† used data from a sample of parents to investigate the ways in which parents monitor their children's use of video games. The sample of parents consisted of 427 people who responded to a survey conducted on an Amazon-operated marketplace where people can complete surveys in exchange for compensation. (a) Do you think that the sample of parents was selected in a way that makes it reasonable to think it is representative of the population of all parents? O No, the parents in the study were ones who voluntarily responded to an online survey and therefore are not likely to be representative of the population of all parents. Yes, parents who respond to online surveys tend to be representative of the population. O No, they should have allowed parents to call in to complete the survey as well as fill it out online. O No, the sample size was not large enough. O Yes, the parents in the study were randomly…arrow_forward
- The drug X is marketed to help protect against male pattern baldness, and it also may protect against prostate cancer. A large sampleof healthy men over age 60 were randomly assigned to receive either a daily drug X pill or a placebo. The study lasted nine years and the men had annual check-ups and a biopsy at the end of the study. Prostate cancer was found in 815 of 4368 men taking drug X and in 1176 of the 4698 men taking a placebo. What kind of a study is this and what mesure of assocation (rd, rr, or) can be used and why?arrow_forwardstate whether the investigation in question is an observational study or a designed experiment. Justify your answer in each case. Aspirin and Cardiovascular Disease. In the article by P. Ridker et al. titled “A Randomized Trial of Low-dose Aspirin in the Primary Prevention of Cardiovascular Disease inWomen” (New England Journal of Medicine, Vol. 352, pp. 1293–1304), the researchers noted that “We randomly assigned 39,876 initially healthy women 45 years of age or older to receive 100 mgof aspirin or placebo on alternate days and then monitored them for 10 years for a rst major cardiovascular event (i.e., nonfatal myocardial infarction, nonfatal stroke, or death from cardiovascular causes).”arrow_forwardLecturers at a university intend to see the effect of stress relief strategies such as deep breathing and relaxation techniques to the student performance in the final exam. For this reason, they assigned students of the same year in two different cohorts. More precisely, students in Cohort 1 did not do any relaxation techniques before the exam, while students in Cohort 2 performed a full range of the relaxation techniques approved by the British Psychological Society. The average mark of a random sample of 17 students from Cohort 1 was 61, with a standard deviation of 17, while the average mark of a random sample of 11 students from Cohort 2 was 67 with a standard deviation of 19. (a) Test whether the variances of marks for the two cohorts are the same at the 5% significance level. (b) Test the hypothesis that the average mark in the exam for Cohort 1 students isthe same as that for students of Cohort 2 at the 5% significance level. For this test, what is the p-value? (c) What…arrow_forward
- Lecturers at a university intend to see the effect of stress relief strategies such as deep breathing and relaxation techniques to the student performance in the final exam. For this reason, they assigned students of the same year in two different cohorts. More precisely, students in Cohort 1 did not do any relaxation techniques before the exam, while students in Cohort 2 performed a full range of the relaxation techniques approved by the British Psychological Society. The average mark of a random sample of 17 students from Cohort 1 was 61, with a standard deviation of 17, while the average mark of a random sample of 11 students from Cohort 2 was 67 with a standard deviation of 19. a) Calculate a 95% confidence interval for the difference in average marks in theexam for the two cohorts of students. Explain the meaning of the 95% confidence interval that you have calculated.arrow_forwardThe Commissioner of Health in New York State wanted to study malpractice litigation in New York. A sample of 31 thousand medical records was drawn from a population of 2.7 million patients who were discharged during the year 2009. Using the information obtained from the sample to predict population characteristics with respect to malpractice litigation is an example of ________.arrow_forwardA large toiletry distributor claims that 35% of all individuals who purchase toilet paper from the stores that carry its product choose original toilet paper, 28% choose sensitive toilet paper, 20% choose ultra-strong toilet paper, and 17% choose ultra-soft toilet paper. To investigate this claim, researchers collected data from a random sample of customers in a large city. The results were 170 packages of original, 105 sensitive, 80 ultra-strong, and 45 ultra-soft toilet paper purchases. Are the data from the sample consistent with the distributor's claim? Conduct an appropriate statistical test at the 5% significance level to support your conclusion. Make sure to include parameters, check conditions, and show calculations before formulating a conclusion.arrow_forward
- Glencoe Algebra 1, Student Edition, 9780079039897...AlgebraISBN:9780079039897Author:CarterPublisher:McGraw HillCollege Algebra (MindTap Course List)AlgebraISBN:9781305652231Author:R. David Gustafson, Jeff HughesPublisher:Cengage Learning