Concept explainers
The accompanying summary data on total cholesterol level (mmol/l) was obtained from a sample of Asian postmenopausal women who were vegans and another sample of such women who were omnivores (“Vegetarianism, Bone Loss, and Vitamin D: A Longitudinal Study in Asian Vegans and Non-Vegans,” European J. of Clinical Nutr., 2012: 75–82).
Diet | Sample |
Sample SD | |
Vegan | 88 | 5.10 | 1.07 |
Omnivore | 93 | 5.55 | 1.10 |
Calculate and interpret a 99% CI for the difference between population mean total cholesterol level for vegans and population mean total cholesterol level for omnivores (the cited article included a 95% CI). [Note: The article described a more sophisticated statistical analysis for investigating bone density loss taking into account other characteristics (“
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Chapter 9 Solutions
Student Solutions Manual for Devore's Probability and Statistics for Engineering and the Sciences, 9th
- The article “Arsenic and Mercury in Lake Whitefish and Burbot Near the Abandoned Giant Mine on Great Slave Lake” (P. Cott, B. Zajdlik, et al., Journal of Great Lakes Research, 2016:223–232) presents measurements of arsenic concentrations in fish found in Northern Canada. a) In a sample of 8 whitefish caught in Yellowknife Bay, the mean arsenic concentration in the liver was 0.32 mg/kg, with a standard deviation of 0.05 mg/kg. Find a 95% confidence interval for the concentration in whitefish found in Yellowknife Bay. b) In a sample of 8 whitefish caught in Baker Pond, the mean arsenic concentration in the liver was 0.55 mg/kg, with a standard deviation of 0.36 mg/kg. Should the Student’s t distribution be used to find a 95% confidence interval for the concentration in whitefish found in Baker Pond? If so, find the confidence interval. If not, explain why not.arrow_forwardPassive exposure to environmental tobacco smoke has been associated with growth suppression and an increased frequency of respiratory tract infections in normal children. Is this association more pronounced in children with cystic fibrosis? To answer this question, 43 children (18 girls and 25 boys) attending a 2-week summer camp for cystic fibrosis patients were studied (New England Journal of Medicine, Sept. 20, 1990). Among several variables measured were the child's weight percentile (y) and the number of cigarettes smoked per day in the child's home (x). a. For the 18 girls, the coefficient of correlation between y and x was reported as r = –.50. Interpret - this result. b. Refer to part a. The p-value for testing Ho: p = 0 against H;: p # 0 was reported as p = .03. n Interpret this result. c. For the 25 boys, the coefficient of correlation between y and x was reported asr = -.12. Interpret %3D %3D this result. d. Refer to part c. The p-value for testing Ho: p = 0 against Ha: p #…arrow_forwardThe article "Analysis of Unwanted Fire Alarm: Case Study" (W. Chow, N. Fong, and C. Ho, Journal of Architectural Engineering, 1999:62–65) presents a count of the number of false alarms at several sites. The numbers of false alarms each month, divided into those with known causes and those with unknown causes, are given in the following table. Can you conclude that the proportion of false alarms whose cause is known differs from month to month? Month 1 2 3 7 8 9 10 11 12 4 5 6 20 13 21 26 23 18 14 10 20 20 18 14 Unknown 12 2 16 12 22 30 32 32 14 16 10 12 Knownarrow_forward
- Speed, size and strength are thought to be important factors in football performance. The paper “Physical and Performance Characteristics of NCAA Division I Football Players” (Research Quarterly for Exercise and Sport (1990): 395-401) reported on physical characteristics of Division I starting football players in the 1988 football season. Information for teams ranked in the top 30 was easily obtained, and it was reported that the mean weight of starters on top-30 teams was 110 kg. A sample of 23 starting players (various positions were represented) from Division I teams that were not ranked in the top 20 resulted in a sample mean of 103.3 kg and a sample standard deviation of 16.3 kg. Is there sufficient evidence to conclude that the mean weight for non-top-20 starters is less than the known value for top-20 teams? Conduct hypothesis test using α=.01arrow_forwardTwenty samples of students from the first year were taken for the study related to student emotional intelligence (EQ) in a university. The researcher has collected the data for a few variables: gender, academic performance, and emotional intelligence (EQ) test score. EQ Training and Coaching(T & C) Programme EQ Score No Gender CGPA (Before Attend T & C) EQ Score (After Attend T & C) 1 Male 2.10 444 526 2 Female 4.00 780 862 3 Male 2.30 475 557 4 Male 2.40 490 572 5 Female 3.80 755 837 6 Female 3.90 766 848 7 Male 2.70 540 622 Male 3.10 623 705 9 Male 2.90 600 682 10 Male 3.00 620 702 11 Male 2.50 505 590 12 Female 3.20 640 725 13 Male 2.60 523 608 14 Female 3.40 700 785 15 Female 3.50 710 795 16 Female 3.60 726 811 17 Female 3.70 740 825 18 Male 2.80 550 635 19 Female 3.30 685 770 20 Male 2.20 460 545 Table 1 Remarks: (1) Range of CGPA: 0 to 4 (2) Range of EQ Score: 0 to 900 To analysis the relationship between students' academic performance and emotional intelligence (EQ) in the…arrow_forwardTwenty samples of students from the first year were taken for the study related to student emotional intelligence (EQ) in a university. The researcher has collected the data for a few variables: gender, academic performance, and emotional intelligence (EQ) test score. EQ Training and Coaching(T & C) Programme EQ Score No Gender CGPA (Before Attend T & C) EQ Score (After Attend T & C) 1 Male 2.10 444 526 2 Female 4.00 780 862 3 Male 2.30 475 557 4 Male 2.40 490 572 5 Female 3.80 755 837 6 Female 3.90 766 848 7 Male 2.70 540 622 Male 3.10 623 705 9 Male 2.90 600 682 10 Male 3.00 620 702 11 Male 2.50 505 590 12 Female 3.20 640 725 13 Male 2.60 523 608 14 Female 3.40 700 785 15 Female 3.50 710 795 16 Female 3.60 726 811 17 Female 3.70 740 825 18 Male 2.80 550 635 19 Female 3.30 685 770 20 Male 2.20 460 545 Table 1 Remarks: (1) Range of CGPA: 0 to 4 (2) Range of EQ Score: 0 to 900 Use the sample data from table 1, perform hypothesis testing to determine whether there is a difference in the…arrow_forward
- Each year the US Environmental Protection Agency (EPA) releases fuel economy data on cars manufactured in that year. Below are summary statistics on fuel efficiency (in miles/gallon) from random samples of cars with manual and automatic transmissions manufactured in 2012. Do these data provide strong evidence of a difference between the average fuel efficiency of cars with manual and automatic transmissions in terms of their average city mileage? Assume that conditions for inference are satisfied. Mean SD City MPG, Automatic 16.12 City MPG, Manual 19.85 4.51 3.58 26 26 357 25 15 automatic. manual City MPG The hypotheses for this test are: Ho: automatic Pmanual Ha: Pautomatic Hmanual Ho: Pautomatic Hmanual Ha: Pautomatic? Hmanual Ho: Hautomatic Pmanual Ha: Pautomatic Pmanual The test statistic is: x (please round to two decimal places) The p-value is: x (please round to four decimal places) Internret the resultarrow_forwardThe 5-year incidence of cardiovascular disease (CVD) in relation to smoking status was determined in a population sample of 1000 men, 18 years and older. At baseline, 30% of the men were classified as being current smokers and 70% as being non-smokers. At the end of the follow-up, 60 CVD events had occurred among the smokers and 70 events among the non-smokers. Construct a 2 x 2 table based on the data providedarrow_forwardThe paper “Contemporary College Students and Body Piercing” (Journal of Adolescent Health [2004]: 58-61) described a survey of 450 undergraduate students at a state university in the southwest region of the United States. Each student in the sample was classified according to class standing (freshman, sophomore, junior, or senior) and body art category (body piercings only, tattoos only, both tattoos and body piercings, no body art). Use the data in the accompanying table to determine if there is evidence that there is an association between class standing and response to the body art question. Assume that it is reasonable to regard the sample of students as representative of the students at this university. Use α = .01.arrow_forward
- 6. Binge-watching a television show might not be the best way to enjoy a television series (Horvath et al., 2017). Participants in an experiment were in a group that either watched an entire tv series during daily one-hour sessions or watched all the episodes during a single binge session. Participants were asked to rate their enjoyment of the t.v. series on a scale of 0-100. Data like those observed by the author are listed below: Binge-watched 87 Daily-watched 84 71 100 73 87 86 97 78 92 a. Is there a difference in the level of enjoyment based on whether the series was binge-watched or watched on a daily basis? Use a two-tailed test at the a = 0.05 level of significance? b. Do the data analysis in SPSS in addition to your hand calculations. Attach a printout of your results.arrow_forwardAn article describes several studies of the failure rate of defibrillators used in the treatment of heart problems. In one study conducted by the Mayo Clinic, it was reported that failures were experienced within the first 2 years by 16 of 81 patients under 50 years old and 11 of 369 patients ages 50 and older who received a particular type of defibrillator. Assume it is reasonable to regard these two samples as representative of patients in the two age groups who receive this type of defibrillator. A USE SALT (a) Construct a 95% confidence interval for the proportion of patients under 50 years old who experience a failure within the first 2 years after receiving this type of defibrillator. (Round your answers to three decimal places.) Interpret the interval. O we are 95% confident that the proportion of all patients who experience a failure after receiving this type of defibrillator is within this interval. O we are 95% confident that the proportion of all patients under 50 years old…arrow_forwardTo determine if a training program has improved the average performance of trainees if data is collected from two different groups of managers (one group that has not undertaken the training program and the other group that has completed the training program), the samples are independent dependent correlated matchedarrow_forward
- Glencoe Algebra 1, Student Edition, 9780079039897...AlgebraISBN:9780079039897Author:CarterPublisher:McGraw HillBig 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