Concept explainers
The authors of the paper “Movie Character Smoking and Adolescent Smoking: Who Matters More, Good Guys or Bad Guys?” (Pediatrics [2009]: 135–141) classified characters who were depicted smoking in movies released between 2000 and 2005. The smoking characters were classified according to sex and whether the character type was positive, negative, or neutral. The resulting data are summarized in the accompanying table.
Assume that it is reasonable to consider this sample of smoking movie characters as representative of smoking movie characters. Do the data provide evidence of an association between sex and character type for movie characters who smoke? Use α = 0.05. (Hint: See Example 12.7.)
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Chapter 12 Solutions
Introduction To Statistics And Data Analysis
- The article “HIV-positive Smokers Considering Quitting: Differences by Race/Ethnicity” (E. Lloyd-Richardson, C. Stanton, et al., Am J Health Behav, 2008:3–15) reported that in a group of 230 European-American HIV-positive smokers, 102 of them had used a nicotine patch to try to quit smoking, and in a group of 72 Hispanic-American HIV-positive smokers, 20 had used a nicotine patch. Can you conclude that the proportion of patch users is greater among European-Americans?arrow_forwardThe National Sleep Foundation conducted a survey on the sleep habits of randomly sampled transportation workers and a control sample of non-transportation workers. The results of the survey are shown below. Control Pilots Truck Drivers Train Operators Bus/Taxi/Limo Drivers Less than 6 hours of sleep 35 19 35 29 21 6 to 8 hours of sleep 193 132 117 119 131 More than 8 hours 64 51 51 32 58 Total 292 202 203 180 210 Conduct a hypothesis test to evaluate if these data provide evidence of a difference between the proportions of truck drivers and non-transportation workers (the control group) who get less than 6 hours of sleep per day, i.e. are considered sleep deprived.arrow_forwardA study, which randomly surveyed 3,700 households and drew on this information from the IRS, found that 79% of households have conducted at least one IRA rollover from an employer-sponsored retirement plan. Suppose a recent random sample of 90 households in a certain county was taken and respondents were asked whether they had ever funded an IRA account with a rollover from an employer-sponsored retirement plan. Based on the sample data below, can you conclude at the 0.10 level of significance that the proportion of households in the county that have funded an IRA with a rollover is different from the proportion for all households reported in the study? 77 respondents said they had funded an account; 13 respondents said they had notarrow_forward
- A low-level CDC bureaucrat wants to please his boss by gathering evidence thatthe current government-mandated shutdown of society is not causing people’s mentalhealth to deteriorate, so that it can safely be continued for several years if anyexpert says it’s necessary.He polls a random sample of 1600 citizens, gathering data on such items asincome loss, weight gain, access to toilet paper, hours spent binge-watchingNetflix, and number of injuries caused by household fights, and compiles all thisinto a scientifically-weighted “misery index”.The mean misery index from the sample is 99.2; it seems reasonable to use apopulation standard deviation σ = 19.1.a) Does this information provide significant evidence (at the 5% level) that thenationwide mean misery index is less than 100? Set up appropriate null andalternative hypotheses, calculate the appropriate test statistic, find the P-value,and state your conclusion. (10)b) A CDC press release publishing the results of this study claims that…arrow_forwardA low-level CDC bureaucrat wants to please his boss by gathering evidence thatthe current government-mandated shutdown of society is not causing people’s mentalhealth to deteriorate, so that it can safely be continued for several years if anyexpert says it’s necessary.He polls a random sample of 1600 citizens, gathering data on such items asincome loss, weight gain, access to toilet paper, hours spent binge-watchingNetflix, and number of injuries caused by household fights, and compiles all thisinto a scientifically-weighted “misery index”.The mean misery index from the sample is 99.2; it seems reasonable to use apopulation standard deviation σ = 19.1.a) Does this information provide significant evidence (at the 5% level) that thenationwide mean misery index is less than 100? Set up appropriate null andalternative hypotheses, calculate the appropriate test statistic, find the P-value,and state your conclusion. b) A CDC press release publishing the results of this study claims that…arrow_forwardThe article “The Effects of a Low-Fat, Plant-Based DietaryIntervention on Body Weight, Metabolism, and InsulinSensitivity in Postmenopausal Women” (Amer. J. of Med.,2005: 991–997) reported on the results of an experiment inwhich half of the individuals in a group of 64 postmenopausaloverweight women were randomly assigned to a particularvegan diet, and the other half received a diet based on NationalCholesterol Education Program guidelines. The sample meandecrease in body weight for those on the vegan diet was 5.8kg, and the sample SD was 3.2, whereas for those on the control diet, the sample mean weight loss and standard deviationwere 3.8 and 2.8, respectively. Does it appear the true averageweight loss for the vegan diet exceeds that for the control dietby more than 1 kg? Carry out an appropriate test of hypotheses at significance level .05 based on calculating a P-valuearrow_forward
- . Although there is a popular belief that herbal remedies such as Ginkgo biloba and Ginseng may improve learning and memory in healthy adults, these effects are usually not supported by wellcontrolled research (Persson, Bringlov, Nilsson, and Nyberg, 2004). In a typical study, a researcher obtains a sample of n = 16 participants and has each person take the herbal supplements every day for 90 days. At the end of the 90 days, each person takes a standardized memory test. For the general population, scores from the test form a normal distribution with a mean of μ = 50 and a standard deviation of σ = 12. The sample of research participants had an average of M = 54. Assuming a two-tailed test, state the null hypothesis in a sentence that includes the two variables being examined. Using the standard 4-step procedure, conduct a two-tailed hypothesis test with α = .05 to evaluate the effect of the supplements.arrow_forwardA cross-sectional study is conducted to investigate cardiovascular disease (CVD) risk factors among a sample of patients seeking medical care at one of three local hospitals. A total of 500500 patients are enrolled. Based on the following data, we would like to determine if there is a significant association between the family history of CVD and the enrollment site. Enrollment Site Family History of CVD Hospital 1 Hospital 2 Hospital 3 Total Yes 34 8 58 100 No 104 72 224 400 Total 138 80 282 500 Given: The value of the test statistic is χ2= 6.912 Use α=0.1 as the level of significance. The superintendent of Hospital 2 performed the Goodness of Fit Test to test whether 25% of the patients go to Hospital 1, 15% of the patients go to Hospital 2 and 60% of the patients go to Hospital 3. Given: The superintendent found that the pp-value for the test is 0.25091 Let: p1=p1= be the proportion of patients at Hospital 1 p2=p2= be the proportion of patients at…arrow_forwardAnother experiment involving processor speed (Sp) and size of random access memory (RAM) for computers produced the following data Sp1 Sp2 RAM 1 48 37 38 35 37 39 RAM 2 30 35 31 22 26 30 Are the factors Sp and RAM or their interaction statistically significant?arrow_forward
- A travel agency is interested in finding out if different age groups frequent different Spring Break destinations, in order to better target the appropriate audiences. A random sample of college Spring Break vacationers produces the results given in the table below. Is there enough evidence at the 0.025 level of significance to show that there is a relationship between age (by college classification) and destination? Observed Sample of College Students Beach Mountains City Home Total Freshman 28 17 20 22 87 Sophomore 24 14 15 3 56 Junior 24 15 17 15 71 Senior 10 12 3 12 37 Total 86 58 55 52 251 Step 3 of 4: Compute the value of the test statistic. Round your answer to three decimal places, if necessary. (Note: If calculating by hand, be sure to use at least six decimal places in numbers for all intermediate calculations to ensure accuracy of the result.) Step 4 of 4: Draw a conclusion and interpret the decisionarrow_forwardA bank would like to study the waiting time of serving customers during the noon-to- 1 p.m. lunch period of their branches located at two places; in a commercial district of a city and in a residential area. Data are collected from a random sample of 20 customers, and the waiting time (in minutes) are recorded from both branches as follows: Commercial District Residential Area 4.21 5.55 3.02 5.13 4.77 9.66 5.90 8.02 5.79 8.73 2.34 3.54 3.20 4.50 6.10 3.82 8.01 8.35 6.68 5.64 At 1 percent significance level, can we conclude that the customers at branch which located in the residential area need to wait longer compared to the customers who entered bank branch in the commercial district?arrow_forwardConsider the following measurements of blood hemoglobin concentrations (in g/dL) from three human populations at different geographic locations: population1 = [ 14.7 , 15.22, 15.28, 16.58, 15.10 ] population2 = [ 15.66, 15.91, 14.41, 14.73, 15.09] population3 = [ 17.12, 16.42, 16.43, 17.33] For the three populations, what is the value of SSgroups in the ANOVA table? For the three populations, what is the value of SSerror in the ANOVA table?arrow_forward
- Glencoe Algebra 1, Student Edition, 9780079039897...AlgebraISBN:9780079039897Author:CarterPublisher:McGraw Hill