Introductory Statistics (10th Edition)
10th Edition
ISBN: 9780321989178
Author: Neil A. Weiss
Publisher: PEARSON
expand_more
expand_more
format_list_bulleted
Concept explainers
Videos
Question
Chapter 11.2, Problem 76E
a.
To determine
Conduct the required hypothesis to test by using two-standard-deviations
b.
To determine
Obtain the 80% confidence interval using two-standard-deviations F-interval procedure to obtain the ratio of the population standard deviations of IQs with and without early postnatal dexamethasone therapy.
c.
To determine
Obtain normal probability plot for each sample.
d.
To determine
Decide whether conducting inferences as did in part (a) and (b) seem reasonable or not based on the results from part (c) and to explain the reason.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
Dexamethasone and IQ. In the paper “Outcomes at School Age After Postnatal Dexamethasone Therapy for Lung Disease of Prematurity” (New England Journal of Medicine, Vol. 350, No. 13, pp. 1304–1313), T. Yeh et al. studied the outcomes at school age in children who had participated in a double-blind, placebo-controlled trial of early postnatal dexamethasone therapy for the prevention of chronic lung disease of prematurity. All of the infants in the study had had severe respiratory distress syndrome requiring mechanical ventilation shortly after birth. On the WeissStats site, we provide the school-age IQs of the 74 children in the control group, based on the study results. Use the technology of your choice to do the following.
a. Obtain a normal probability plot, boxplot, histogram, and stemand-leaf diagram of the data.
b. Based on your results from part (a), can you reasonably apply one-standard-deviation χ2-procedures to the data? Explain your reasoning.
c. Overall, IQs of school-age…
In its January 25, 2012, issue, the Journal of the American Medical Association reported on the effects of overconsumption of low, normal, and high protein diets on weight gain, energy expenditure, and body composition. Researchers conducted a single blind, randomized controlled trial of 25 U.S. adults. The subjects were healthy, weight-stable, male and female volunteers, aged 18 to 35 years. All subjects consumed a weight-stabilizing diet for 13 to 25 days. Afterwards, the researchers randomly assigned participants to diets containing various percentages of energy from protein: 5% (low protein), 15% (normal protein), or 25% (high protein). The subjects were not aware of the specific protein level diet to which they were assigned. On these diets the researchers overfed the participants during the last 8 weeks of their 10 to 12 week stay in the inpatient metabolic unit. The goal was to investigate the effect of overconsumption of protein on weight gain, energy expenditure, and body…
The article “Treadmill Exercise and Resistance Training in Patients With Peripheral Arterial Disease With and Without Intermittent Claudication. A Randomized Controlled Trial” (M. McDermott, P. Ades, et al., Journal of the American Medical Association, 2009:165–174) reported the results of a study to determine whether treadmill exercise could improve the walking ability of patients suffering from claudication, which is pain caused by insufficient blood flow to the muscles of the legs. A sample of 48 patients walked on a treadmill for six minutes every day. After six months, the mean distance walked in six minutes was 348 m, with a standard deviation of 80 m. For a control group of 46 patients who did not walk on a treadmill, the mean distance was 309 m with a standard deviation of 89 m. Find a 95% confidence interval for the difference in mean distance walked between the two groups of patients.
Chapter 11 Solutions
Introductory Statistics (10th Edition)
Ch. 11.1 - What is meant by saying that a variable has a...Ch. 11.1 - How are different chi-square distributions...Ch. 11.1 - Two 2-curves have degrees of freedom 12 and 20,...Ch. 11.1 - The t-table has entries for areas of 0.10, 0.05,...Ch. 11.1 - Prob. 5ECh. 11.1 - Prob. 6ECh. 11.1 - In Exercises 11.511.2, use Table VII to find the...Ch. 11.1 - Prob. 8ECh. 11.1 - Prob. 9ECh. 11.1 - Prob. 10E
Ch. 11.1 - Prob. 11ECh. 11.1 - Prob. 12ECh. 11.1 - When you use chi-square procedures to make...Ch. 11.1 - Give two situations in which making an inference...Ch. 11.1 - Prob. 15ECh. 11.1 - In each of Exercises 11.1511.20, we have provided...Ch. 11.1 - In each of Exercises 11.1511.20, we have provided...Ch. 11.1 - Prob. 18ECh. 11.1 - In each of Exercises 11.1511.20, we have provided...Ch. 11.1 - Prob. 20ECh. 11.1 - Prob. 21ECh. 11.1 - Prob. 22ECh. 11.1 - Preliminary data analyses and other information...Ch. 11.1 - Preliminary data analyses and other information...Ch. 11.1 - Prob. 25ECh. 11.1 - Prob. 26ECh. 11.1 - In Exercises 11.2711.32, use Procedure 11.2 on...Ch. 11.1 - Prob. 28ECh. 11.1 - Prob. 29ECh. 11.1 - In Exercises 11.2711.32, use Procedure 11.2 on...Ch. 11.1 - Prob. 31ECh. 11.1 - Prob. 32ECh. 11.1 - Prob. 33ECh. 11.1 - Prob. 34ECh. 11.1 - Prob. 35ECh. 11.1 - In each of Exercises 11.3311.36, use the...Ch. 11.1 - Body Temperature. A study by researchers at the...Ch. 11.1 - Dexamethasone and IQ. In the paper Outcomes at...Ch. 11.1 - Forearm Length. In 1903, K. Pearson and A. Lee...Ch. 11.1 - Prob. 40ECh. 11.2 - How many numbers of degrees of freedom does an...Ch. 11.2 - What symbol is used to denote the F-value having...Ch. 11.2 - Prob. 44ECh. 11.2 - An F-curve has df = (12, 7). What is the number of...Ch. 11.2 - Prob. 46ECh. 11.2 - Prob. 47ECh. 11.2 - In Exercises 11.4711.54, use Table VIII and, if...Ch. 11.2 - Prob. 49ECh. 11.2 - Prob. 50ECh. 11.2 - Prob. 51ECh. 11.2 - In Exercises 11.4711.54, use Table VIII and, if...Ch. 11.2 - In Exercises 11.4711.54, use Table VIII and, if...Ch. 11.2 - Prob. 54ECh. 11.2 - In using F-procedures to make inferences for two...Ch. 11.2 - Give two situations in which comparing two...Ch. 11.2 - Prob. 57ECh. 11.2 - Prob. 58ECh. 11.2 - Prob. 59ECh. 11.2 - Prob. 60ECh. 11.2 - In each of Exercises 11.5711.62, we have provided...Ch. 11.2 - Prob. 62ECh. 11.2 - Prob. 63ECh. 11.2 - Preliminary data analyses and other information...Ch. 11.2 - Prob. 65ECh. 11.2 - Preliminary data analyses and other information...Ch. 11.2 - Prob. 67ECh. 11.2 - Preliminary data analyses and other information...Ch. 11.2 - Prob. 69ECh. 11.2 - Prob. 70ECh. 11.2 - Prob. 71ECh. 11.2 - Prob. 72ECh. 11.2 - Prob. 73ECh. 11.2 - Prob. 74ECh. 11.2 - The Etruscans. Anthropologists are still trying to...Ch. 11.2 - Prob. 76ECh. 11.2 - RBC Transfusions. In the article Reduction in Red...Ch. 11.2 - Prob. 79ECh. 11 - What distribution is used in this chapter to make...Ch. 11 - Fill in the blanks. a. A 2-curve is _____ skewed....Ch. 11 - When you use the one-standard-deviation 2-test or...Ch. 11 - Prob. 4RPCh. 11 - Prob. 5RPCh. 11 - Prob. 6RPCh. 11 - Prob. 7RPCh. 11 - Prob. 8RPCh. 11 - What distribution is used in this chapter to make...Ch. 11 - Fill in the blanks: a. An F-curve is ____ skewed....Ch. 11 - When you use the two-standard-deviations F-test....Ch. 11 - Prob. 12RPCh. 11 - Prob. 13RPCh. 11 - Prob. 14RPCh. 11 - Prob. 15RPCh. 11 - Prob. 16RPCh. 11 - Prob. 17RPCh. 11 - Prob. 18RPCh. 11 - Prob. 19RPCh. 11 - Prob. 20RPCh. 11 - Prob. 21RPCh. 11 - Prob. 22RPCh. 11 - Prob. 23RPCh. 11 - Microwave Popcorn. Two brands of microwave...Ch. 11 - Recall from Chapter 1 (see page 34) that the Focus...Ch. 11 - At the beginning of this chapter, we discussed...
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, statistics and related others by exploring similar questions and additional content below.Similar questions
- The article “Treadmill Exercise and Resistance Training in Patients With Peripheral Arterial Disease With and Without Intermittent Claudication. A Randomized Controlled Trial” (M. McDermott, P. Ades, et al., Journal of the American Medical Association, 2009:165–174) reported the results of a study to determine whether treadmill exercise could improve the walking ability of patients suffering from claudication, which is pain caused by insufficient blood flow to the muscles of the legs. A sample of 48 patients walked on a treadmill for six minutes every day. After six months, the mean distance walked in six minutes was 348 meters, with a standard deviation of 80 m. For a control group of 46 patients who did not walk on a treadmill, the mean distance was 309 m with a standard deviation of 89 m. Can you conclude that the mean distance walked for patients using a treadmill is greater than the mean for the controls? Use the α = 0.05 level of significance.arrow_forwardIn a study conducted in the Science Department of Faculty of Science, Technology and Human Development in a University; the researcher examined the influence of the drug succinylcholine on the circulation levels of androgens in the blood. Blood samples from wild, free-ranging deer were obtained via the jugular vein immediately after an intramuscular injection of succinylcholine using darts and a capture gun. Deer were bled again approximately 30 minutes after the injection and then released. The level of androgens at time of capture and 30 minutes later, measured in nanograms per milliliter (ng/ml), for 15 deers as in Table Q1. Assuming that the populations of androgen at time of injection and 30 minutes later are normally distributed:i) Find the average and standard deviation of this studyii)Determine the critical region of this problem.iii) Test at the 0.05 level of significance whether the androgen concentrations are altered after 30 minutes of restraint.arrow_forwardLeisure Activities and Dementia. An article appearing in the Los Angeles Times discussed the study “Leisure Activities and the Risk of Dementia in the Elderly” (New England Journal of Medicine, Vol. 348) by J.Verghese et al. The article in the Times, titled “Crosswords Reduce Risk of Dementia,” contained the following statement: “Elderly people who frequently read, do crossword puzzles, practice a musical instrument or play board games cut their risk of Alzheimer’s and other forms of dementia by nearly two-thirds compared with people who seldom do such activities.” Comment on thestatement in quotes, keeping in mind the type of study for which causation can be reasonably inferred.arrow_forward
- 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 mg of aspirin or placebo on alternate days and then monitored them for 10 years for a first major cardiovascular event (i.e., nonfatal myocardial infarction, nonfatal stroke, or death from cardiovascular causes).”arrow_forwardA study of “adverse symptoms” in users of over-the-counter pain relief medications assigned subjects at random toone of two common pain relievers: acetaminophen and ibuprofen. In all, 650 subjects took acetaminophen, and 44experienced some adverse symptom. Of the 347 subjects who took ibuprofen, 49 had an adverse symptom. Is thisconvincing evidence that the two pain relievers differ in the proportion of people who experience an adverse symptom?arrow_forwardIn randomized, double-blind clinical trials of a new vaccine, children were randomly divided into two groups. Subjects in group 1 received the new vaccine while subjects in group 2 received a control vaccine. After the second dose, 116 of 651 subjects in the experimental group (group 1) experienced fever as a side effect. After the second dose, 73 of 532 of the subjects in the control group (group 2) experienced fever as a side effect. Does the evidence suggest that a higher proportion of subjects in group 1 experienced fever as a side effect than subjects in group 2 at the α=0.10 level of significance? #1 Find the test statistic for this hypothesis test.arrow_forward
- High levels of blood sugar are associated with an increased risk of type 2 diabetes. A levelhigher than normal is referred to as “impaired fasting glucose.” The article “Association ofLow-Moderate Arsenic Exposure and Arsenic Metabolism with Incident Diabetes andInsulin Resistance in the Strong Heart Family Study” (M. Grau-Perez, C. Kuo, et al.,Environmental Health Perspectives, 2017, online) reports a study in which 47 of 155 peoplewith impaired fasting glucose had type 2 diabetes. Consider this to be a simple randomsample. a) Find a 95% confidence interval for the proportion of people with impaired fasting glucose who have type 2 diabetes. b) Find a 99% confidence interval for the proportion of people with impaired fasting glucose who have type 2 diabetes. c) A doctor claims that less than 35% of people with impaired fasting glucose have type 2 diabetes. With what level of confidence can this claim be made?arrow_forwardLandolt et al. (A-26) examined rates of posttraumatic stress disorder (PTSD) in mothers and fathers. Parents were interviewed 5 to 6 weeks after an accident or a new diagnosis of cancer or diabetes mellitus type I for their child. Twenty-eight of the 175 fathers interviewed and 43 of the 180 mothers interviewed met the criteria for current PTSD. Is there sufficient evidence for us to conclude that fathers are less likely to develop PTSD than mothers when a child is traumatized by an accident, cancer diagnosis, or diabetes diagnosis? Let alpha = 0.05arrow_forwardA U.S. study published in The American Journal of Preventive Medicine compared state-level prevalence of firearm ownership in 2002 with state-level rates of firearm assault and firearm robbery in the subsequent year. The investigators found a positive association - meaning that states with higher prevalence of firearm ownership also tended to be the states with higher rates of firearm assault. Which design best describes this study? a)Observational cohort study b)Randomized trial c)Case-control study d)Ecological studyarrow_forward
- The Diabetes Control and Complications trial research group, randomly assigned volunteers with type 1 (insulin-dependent) diabetes mellitus, but without retinopathy, either to a conventional treatment or to a more intensive treatment aimed at maintaining normal blood glucose levels. The volunteers' health was monitored closely for approximately six years. By the end of the study, 91 patients out of 378 in the conventional treatment group had developed retinopathy, whereas 23 out of 348 in the intensive treatment group had developed retinopathy. Test whether the rates of retinopathy differed significantly between the two treatment groups, if they did, which rate was significantly lower. 1. Provide the null hypothesis 2. Provide the alternative hypotheses 3. calculate the appropriate test statistic. Show all work 4. Identify the p-value for that test statistic 5. Using the p-value method and an alpha level of 0.02 state what your conclusions are regarding the null hypothesis, and…arrow_forwardThe Diabetes Control and Complications trial research group, randomly assigned volunteers with type 1 (insulin-dependent) diabetes mellitus, but without retinopathy, either to a conventional treatment or to a more intensive treatment aimed at maintaining normal blood glucose levels. The volunteers' health was monitored closely for approximately six years. By the end of the study, 91 patients out of 378 in the conventional treatment group had developed retinopathy, whereas 23 out of 348 in the intensive treatment group had developed retinopathy. Test wether the rates of retionpathy differed significantly betweenthe two treatment groups, if they did, which rate was significantly lower. 1. Provide the null hypothesis 2. Provide the alternative hypotheses 3. calculate the appropriate test statistic. Show all work 4. Indentify the p-value for that test statistic 5. Using the p-vlaue method and an alpha level of 0.02 state what your conclusions is regarding the null hypothesis, and…arrow_forwardNCI Cancer Bulletin, December 2, 2008 Volume 5 / Number 24 Title of the article: After Menopause, Weight Affects Breast Cancer Rates More than Mammography Use Women who are overweight or obese after menopause face an increased risk of breast cancer, but a large prospective cohort study indicates that the frequency of mammography use and screening accuracy are not the primary explanations for higher rates of breast cancer in these women. The same is true of large, invasive breast cancer tumors and advanced stage disease; risk increases with weight, but higher rates are not explained by the frequency or accuracy of screening mammography before breast cancer was diagnosed. The study appears in the December 3 Journal of the National Cancer Institute. Dr. Karla Kerlikowske of the San Francisco Veterans Affairs Medical Center and colleagues gathered data on 287,115 postmenopausal women who were registered in the Breast Cancer Surveillance Consortium database. Reflecting a trend in the…arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
MATLAB: An Introduction with ApplicationsStatisticsISBN:9781119256830Author:Amos GilatPublisher:John Wiley & Sons Inc
Probability and Statistics for Engineering and th...StatisticsISBN:9781305251809Author:Jay L. DevorePublisher:Cengage Learning
Statistics for The Behavioral Sciences (MindTap C...StatisticsISBN:9781305504912Author:Frederick J Gravetter, Larry B. WallnauPublisher:Cengage Learning
Elementary Statistics: Picturing the World (7th E...StatisticsISBN:9780134683416Author:Ron Larson, Betsy FarberPublisher:PEARSON
The Basic Practice of StatisticsStatisticsISBN:9781319042578Author:David S. Moore, William I. Notz, Michael A. FlignerPublisher:W. H. Freeman
Introduction to the Practice of StatisticsStatisticsISBN:9781319013387Author:David S. Moore, George P. McCabe, Bruce A. CraigPublisher:W. H. Freeman
MATLAB: An Introduction with Applications
Statistics
ISBN:9781119256830
Author:Amos Gilat
Publisher:John Wiley & Sons Inc
Probability and Statistics for Engineering and th...
Statistics
ISBN:9781305251809
Author:Jay L. Devore
Publisher:Cengage Learning
Statistics for The Behavioral Sciences (MindTap C...
Statistics
ISBN:9781305504912
Author:Frederick J Gravetter, Larry B. Wallnau
Publisher:Cengage Learning
Elementary Statistics: Picturing the World (7th E...
Statistics
ISBN:9780134683416
Author:Ron Larson, Betsy Farber
Publisher:PEARSON
The Basic Practice of Statistics
Statistics
ISBN:9781319042578
Author:David S. Moore, William I. Notz, Michael A. Fligner
Publisher:W. H. Freeman
Introduction to the Practice of Statistics
Statistics
ISBN:9781319013387
Author:David S. Moore, George P. McCabe, Bruce A. Craig
Publisher:W. H. Freeman
Hypothesis Testing - Solving Problems With Proportions; Author: The Organic Chemistry Tutor;https://www.youtube.com/watch?v=76VruarGn2Q;License: Standard YouTube License, CC-BY
Hypothesis Testing and Confidence Intervals (FRM Part 1 – Book 2 – Chapter 5); Author: Analystprep;https://www.youtube.com/watch?v=vth3yZIUlGQ;License: Standard YouTube License, CC-BY