Concept explainers
The Left Ventricular Mass lndex (LVMI) is a measure of the enlargement of the left side of the heart and is expressed in the units (gm/ht(m)2.7). High values may predict subsequent cardiovascular disease in children as they get older (Urbina et al., [11]). A study is performed to relate the level of LVMI to blood pressure category in children and adolescents age 10–18. The bp level of children was categorized as either Normal (bpcat = 1 or bp percentile < 80% for a given age, gender, and height), Pre-Hypertensive (bpcat = 2 or bp percentile ≥ 80% and bp percentile < 90%), or Hypertensive (bpcat = 3 or bp percentile ≥ 90%). The data are available in the data set LVM.XLS at www.cengagebrain.com
Based on the box plot, does the arithmetic
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- Find the mean hourly cost when the cell phone described above is used for 240 minutes.arrow_forwardSulfur compounds cause "off‑odors" in wine, so winemakers want to know the odor threshold, the lowest concentration of a compound that the human nose can detect. The odor threshold for dimethyl sulfide (DMS) in trained wine tasters is about 25micrograms per liter of wine (?g/L ). The untrained noses of consumers may be less sensitive, however. The DMS odor thresholds for 10 untrained students are given. 30 30 42 35 22 33 31 29 19 23 SOLVE: We have assumed that we have a random sample and that the population from which we are sampling is Normal. Find ?¯ . (Enter your answer rounded to one decimal place.) ?¯= ?g/? Find the standard deviation, ??√, of the sampling distribution of ?¯. (Enter your answer rounded to four decimal places.) ??√=arrow_forwardGlaucoma is a leading cause of blindness in the United States, N. Ehlers measured the difference in corneal thickness (in microns) between the two eyes of eight patients. Each patient had one eye that had glaucoma and one eye that was normal. The difference was measured as the corneal thickness of normal eye – corneal thickness of eye with Glaucoma. Corneal thickness is important because it can mask an accurate reading of eye pressure. Use ? = .05 H0: μd=0 H1: μd≠0 T statistic: t = 1.053, P value = 0.327 Degrees of Freedom n-1 = 8-1= 7 critical value 2.3646 If t is less than 2.3646, or greater than 2.3646, reject the null hypothesis Level of significance: α=0.05 question: what a type 1 error and type 2 error would mean. Is it possible that we could have committed a type 2 error in conducting the testarrow_forward
- Glaucoma is a leading cause of blindness in the United States, N. Ehlers measured the difference in corneal thickness (in microns) between the two eyes of eight patients. Each patient had one eye that had glaucoma and one eye that was normal. The difference was measured as the corneal thickness of normal eye – corneal thickness of eye with Glaucoma. Corneal thickness is important because it can mask an accurate reading of eye pressure. Use ? = .05. Q) If a participant has the same corneal thickness in their normal eye as the eye with Glaucoma, what would be the value for difference: measured as the corneal thickness of normal eye – corneal thickness of eye with Glaucoma.arrow_forwardGlaucoma is a leading cause of blindness in the United States, N. Ehlers measured the difference in corneal thickness (in microns) between the two eyes of eight patients. Each patient had one eye that had glaucoma and one eye that was normal. The difference was measured as the corneal thickness of normal eye – corneal thickness of eye with Glaucoma. Corneal thickness is important because it can mask an accurate reading of eye pressure. Use ? = .05. Q)Conduct a hypothesis test to determine if there is sufficient evidence to conclude that corneal thickness is different in normal eyes compared to eyes with glaucoma? Write up your results using the 8 steps.arrow_forwardGlaucoma is a leading cause of blindness in the United States, N. Ehlers measured the difference in corneal thickness (in microns) between the two eyes of eight patients. Each patient had one eye that had glaucoma and one eye that was normal. The difference was measured as the corneal thickness of normal eye – corneal thickness of eye with Glaucoma. Corneal thickness is important because it can mask an accurate reading of eye pressure. Use ? = .05. Hypothesis: H0: μd=0Ha: μd≠0 Using output Test statistics : t=0.134P value=0.897 Degrees of freedom (df): df=7 Level of significance: α=0.05 Decision: P value > 0.05 thus we fails to reject null hypothesis. Question a)Write a report summarizing your findings. When writing the report consider that medical staff estimate that a difference of 4.5 microns or more could impact on their ability to interpret eye pressure correctly. b) Define for the hypothesis stated in part b) what a type 1 error and type 2 error would mean. Is it possible…arrow_forward
- A researcher is interested in testing the relationship between smoking and BMI (kg/m2) in adults aged 30-45. In order to test this association, the researcher divides smoking into currently more than a pack a day, currently less than a pack a day, and never smokers. The following table represents the BMIs for each participant enrolled by their respective smoking category. Current Smoker (≥1pack/day) Current Smoker (<1 pack/day Never Smoked 26.7 29.4 22.1 29.4 28.6 30.4 24.3 27.4 21.3 28.4 23.2 26.4 21.6 20.1 19.7 27.4 20.6 19.8 26.8 19.7 21.6 36.4 19.6 22.3 31.5 21.6 24.3 27.4 21.5 *Continue as though all assumptions for ANOVA are met. A) Calculate the MSW and MSB for the data represented above. B) Carry out a formal test for a one-way analysis of variance among the groups and interpret your results.arrow_forwardWhat does am/n mean ?arrow_forwardSulfur compounds cause "off‑odors" in wine, so winemakers want to know the odor threshold, the lowest concentration of a compound that the human nose can detect. The odor threshold for dimethyl sulfide (DMS) in trained wine tasters is about 25 micrograms per liter of wine (?g/L ). The untrained noses of consumers may be less sensitive, however. The DMS odor thresholds for 10 untrained students are given. 30 30 42 35 22 33 31 29 19 23 (a) Assume that the standard deviation of the odor threshold for untrained noses is known to be ?=7?g/Lσ To access the complete data set, click the link for your preferred software format: Do the three simple conditions hold in this case? Make a stemplot and use it to check the shape of the distribution. (b) STATE: What is the average (mean) DMS odor threshold, ?μ , for all untrained people? PLAN: Using the four‑step process, give a 95%95% confidence interval for the mean DMS odor threshold among all students. SOLVE: We have assumed that we…arrow_forward
- what is the difference between t-statistic and z-statistic ? Compare the t-statistic formula and the z-statistic formula?arrow_forward“Normal” BMI is up to 25 kg/m2. A laboratory study is being conducted to determine energy expenditure for those who are overweight and/or obese. The researchers have enrolled only subjects with BMI above 25.0 and have quantified obesity as “units above normal”. For example, a subject with BMI of 32.3 is recorded as 7.3 (i.e. 32.3 – 25.0 = 7.3). Using this scheme, the mean obesity was found to be 8.7 kg/m2and the standard deviation was 6.4 kg/m2. If we convert the obesity measure used in this study back into conventional BMI (i.e., add 25.0 units to each measurement), what will the standard deviation be? Group of answer choices The standard deviation will be larger on the BMI scale because 25.0 units will be added back. The standard deviation will be the same 6.4 kg/m2 There is not enough information to determine this The standard deviation will be smaller on the BMI scale because, as a percentage of the whole scale, the difference between each subject and the mean will be…arrow_forwardAnkle Brachial Index. The ankle brachial index (ABI) compares the blood pressure of a patient’s arm to the blood pressure of the patient’s leg. The ABI can be an indicator of different diseases, including arterial diseases. A healthy (or normal) ABI is 0.9 or greater. In a study by M. McDermott et al. titled “Sex Differences in Peripheral Arterial Disease: Leg Symptoms and Physical Functioning” (Journal of the American Geriatrics Society, Vol. 51, No. 2, pp. 222–228), the researchers obtained the ABI of 187 women with peripheral arterial disease. The results were a mean ABI of 0.64 with a standard deviation of 0.15. At the 1% significance level, do the data provide sufficient evidence to conclude that, on average, women with peripheral arterial disease have an unhealthy ABI?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 LearningHolt Mcdougal Larson Pre-algebra: Student Edition...AlgebraISBN:9780547587776Author:HOLT MCDOUGALPublisher:HOLT MCDOUGAL