Concept explainers
Association between Glycemic Load and Acne? An article in the Journal of the Academy of Nutrition and Dietetics reported on a study of diet in subjects with moderate to severe acne. Read the excerpts from the abstract and answer the questions that follow. (Source: Burris et al., “Differences in dietary glycemic load and hormones in New York City adults with no or moderate/severe acne,” Journal of the Academy of Nutrition and Dietetics, vol. 117 [September 2017]: 1375-1383)
Methods: Sixtyfour participants (no acne,
Results: Participants with moderate/severe acne consumed greater total carbohydrate compared to participants without acne. Participants with moderate/severe acne had greater insulin compared to participants without acne. Although there were no differences between groups, 61% of participants reported foodinfluenced acne.
a. Was this a controlled experiment or an observational study? Explain how you know.
b. Assuming the study was properly conducted, can we conclude that higher consumption of carbohydrates causes more severe acne? Explain.
Want to see the full answer?
Check out a sample textbook solutionChapter 1 Solutions
Introductory Statistics
Additional Math Textbook Solutions
Statistics: Informed Decisions Using Data (5th Edition)
Statistics Through Applications
Elementary Statistics ( 3rd International Edition ) Isbn:9781260092561
Elementary Statistics (13th Edition)
Elementary Statistics: A Step By Step Approach
- You think that there might be a relationship between income and what type of outdoor activities people participate in. You survey people in Southern California and get the following results for people’s favorite outdoor activities. For those with high incomes, 50 said mountain biking, 30 said surfing, and 20 said hiking. For those with low incomes, 20 said mountain biking, 50 said surfing, and 30 said hiking. Is there a relationship between income and type of outdoor activity? Complete an 8-step hypothesis test on this data.arrow_forwardDoes exposure to classical music (through instrument lessons or concert attendance) improve a child's scholastic performance? In a study, researchers measured the amount of exposure to classical music for a group of children, along with their scores on the state’s academic proficiency exam. The explanatory variable in this study is: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_forward
- Applying the Concepts and SkillsUse the technology of your choice to solve Problems.Smoking and Cotinine. Smoking during pregnancy is hazardousto both the mother and baby. Passive smoking, or inhalation of second-hand smoke, is also a concern. In the article “Detection of Cotinine in Neonate Meconium as a Marker for Nicotine Exposure in Utero” (Eastern Mediterranean Health Journal, Vol. 10, No. 1/2, pp. 96–105), N. Sherif et al. studied whether activesmoking or passive-smoking mothers were passing along harmful chemicals to their babies. The level of cotinine in a newborn’s first meconium, which is the infant’s stool, is reported on the WeissStats site for independent samples of active-, passive-, and nonsmoking mothers. Cotinine levels are measured in nanograms per milliliter (ng/mL). Decide whether presuming that the assumptions of normal populations and equal population standard deviations are met is reasonable.arrow_forwardProfessional Athlete Salaries. From the Statistical Abstract of the United States and the article “Average Salaries in the NBA, NFL, MLB and NHL” by J. Dorish, published on the Yahoo! Contributor Network, we obtained the following data on average professional athletes’ salaries for the years 2005 and 2011.arrow_forwardThe report Controlling Road Rage: A Literature Review and Pilot Study was prepared for the AAA Foundation for Traffic Safety by D. Rathbone and J. Huckabee. The authors discussed the results of a literature review and pilot study on how to prevent aggressive driving and road rage. Road rage is defined as “... an incident in which an angry or impatient motorist or passenger intentionally injures or kills another motorist, passenger, or pedestrian, or attempts or threatens to injure or kill another motorist, passenger, or pedestrian.” One aspect of the study was to investigate road rage as a function of the day of the week. The following table provides a frequency distribution for the days on which 69 road-rage incidents occurred. Day Frequency Sunday 5 Monday 5 Tuesday 11 Wednesday 12 Thursday 11 Friday 18 Saturday 7 At the 5% significance level, do the data provide sufficient evidence to conclude that road-rage incidents are more likely to occur on some days…arrow_forward
- The report Controlling Road Rage: A Literature Review and Pilot Study was prepared for the AAA Foundation for Traffic Safety by D. Rathbone and J. Huckabee. The authors discussed the results of a literature review and pilot study on how to prevent aggressive driving and road rage. Road rage is defined as “… an incident in which an angry or impatient motorist or passenger intentionally injures or kills another motorist, passenger, or pedestrian, or attempts or threatens to injure or kill another motorist, passenger, or pedestrian.” One aspect of the study was to investigate road rage as a function of the day of the week. The following table provides a frequency distribution for the days on which 69 road-rage incidents occurred. Day Frequency Sunday 5 Monday 5 Tuesday 11 Wednesday 12 Thursday 11 Friday 18 Saturday 7 At the 5% significance level, do the data provide sufficient evidence to conclude that road-rage incidents are more likely to occur on…arrow_forwardIn the empirical exercises on earning and height in Chapters 4 and 5, you estimated a relatively large and statistically significant effect of a worker’s height on his or her earnings. One explanation for this result is omitted variable bias: Height is correlated with an omitted factor that affects earnings. For example, Case and Paxson (2008) suggest that cognitive ability (or intelligence) is the omitted factor. The mechanism they describe is straightforward: Poor nutrition and other harmful environmental factors in utero and in early childhood have, on average, deleterious effects on both cognitive and physical development. Cognitive ability affects earnings later in life and thus is an omitted variable in the regression. Suppose that the mechanism described above is correct. Explain how this leads to omitted variable bias in the OLS regression of Earnings on Height. Does the bias lead the estimated slope to be too large or too small? [Hint: Review Equation (6.1)]arrow_forwardBiostatistics is integral to the field of epidemiology, which is defined as study of health and illness in human populations, patterns of health or disease, and the factors that influence these patterns. True Falsearrow_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 Harcourt