![Introductory Statistics, Books a la Carte Plus NEW MyLab Statistics with Pearson eText -- Access Card Package (10th Edition)](https://www.bartleby.com/isbn_cover_images/9780134270364/9780134270364_largeCoverImage.gif)
Concept explainers
Treating Heart Failure. In the journal article “Cardiac- Resynchronization Therapy with or without an Implantable Defibrillator in Advanced Chronic Heart Failure” (New England Journal of Medicine, Vol. 350, pp. 2140–2150), M. Bristow et al. reported the results of a study of methods for treating patients who had advanced heart failure due to ischemic or nonischemic cardiomyopathies. A total of 1520 patients were randomly assigned in a 1:2:2 ratio to receive optimal pharmacologic therapy alone or in combination with either a pacemaker or a pacemaker–defibrillator combination. The patients were then observed until they died or were hospitalized for any cause.
- a. How many treatments were there?
- b. Which group would be considered the control group?
- c. How many treatment groups were there? Which treatments did they receive?
- d. How many patients were in each of the three groups studied?
- e. Explain how a table of random numbers or a random-number generator could be used to divide the patients into the three groups.
![Check Mark](/static/check-mark.png)
Want to see the full answer?
Check out a sample textbook solution![Blurred answer](/static/blurred-answer.jpg)
Chapter 1 Solutions
Introductory Statistics, Books a la Carte Plus NEW MyLab Statistics with Pearson eText -- Access Card Package (10th Edition)
- The Lion’sMane. In a study by P. M.West titled “The Lion’s Mane” (American Scientist, Vol. 93, No. 3, pp. 226–236), the effects of the mane of a male lion as a signal of quality to mates and rivals was explored. Four life-sized dummies of male lions provided a tool for testing female response to the unfamiliar lions whose manes varied by length (long or short) and color (blonde or dark). The female lions were observed to see whether they approached each of the four life-sized dummies. a. experimental units. b. response variable. c. factor(s). d. levels of each factor. e. treatments.arrow_forwardAn article in Knee Surgery, Sports Traumatology, Arthroscopy, "Arthroscopic meniscal repair with an absorbable screw: results and surgical technique," (2005, Vol. 13, pp. 273-279) cites a success rate more than 90% for meniscal tears with a rim width of less than 3 mm, but only a 67% success rate for tears of 3-6 mm. If you are unlucky enough to suffer a meniscal tear of less than 3 mm on your left knee, and one of width 3-6 mm on your right knee, what are the mean and variance of the number of successful surgeries? Assume the surgeries are independent. Round your answers to three decimal places (e.g. 98.765). Mean = i Variance =arrow_forwardAn article in Knee Surgery, Sports Traumatology, Arthroscopy, "Arthroscopic meniscal repair with an absorbable screw: results and surgical technique," (2005, Vol. 13, pp. 273-279) cites a success rate more than 90% for meniscal tears with a rim width of less than 3 mm, but only a 67% success rate for tears of 3-6 mm. If you are unlucky enough to suffer a meniscal tear of less than 3 mm on your left knee, and one of width 3-6 mm on your right knee, what is the probability mass function of the number of successful surgeries, x? Assume the surgeries are independent. Choose the correct answer. O P(x = 0) = 0.2, P(x = 1) = 0.4, P(x = 2) = 0.4 O P(x = 0) = 0.033, P(x = 1) = 0.42, P(x = 2) = 0.603 O P(x = 0) = 0.067, P(x = 1) = 0.364, P(x = 2) = 0.603 O P(x = 0) = 0.033, P(x = 1) = 0.364, P(x = 2) = 0.603 = 0.067, P(x = 1) = 0.42, P(x = 2) = 0.603arrow_forward
- Young Adults at Risk. Research by R. Pyhala et al. shows that young adults who were born prematurely with very low birth weights (below 1500 grams) have higher blood pressure than those born at term. The study can be found in the article, “Blood Pressure Responses to Physiological Stress in Young Adults with Very Low Birth Weight” (Pediatrics, Vol. 123, No. 2, pp. 731–734). The researchers found that systolic blood pressures of young adults who were born prematurely with very low birth weights have mean 120.7 mm Hg and standard deviation 13.8 mm Hg. a. Identify the population and variable. b. For samples of 30 young adults who were born prematurely with very low birth weights, find the mean and standard deviation of all possible sample mean systolic blood pressures. Interpret your results in words. c. Repeat part (b) for samples of size 90.arrow_forwardCloud seeding, a process in which chemicals such as silver iodide and frozen carbon dioxide are introduced by aircraft into clouds to promote rainfall was widely used in the 20-th century. Recent research has questioned its effectiveness [Journal of Atmospheric Research (2010, Vol. 97 (2), pp. 513-525)]. An experiment was performed by randomly assigning 52 clouds to be seeded or not. The amount of rain generated was then measured in acre-feet. Here are the data for the unseeded and seeded clouds: Unseeded: 81.2 26.1 95.0 41.1 28.6 21.7 11.5 68.5 345.5 321.2 1202.6 1.0 4.9 163.0 372.4 244.3 47.3 87.0 26.3 24.4 830.1 4.9 36.6 147.8 17.3 29.0 Seeded: 274.7 302.8 242.5 255.0 17.5 115.3 31.4 703.4 334.1 430.0 1697.8 118.3 198.6 129.6 274.7 119.0 1656.0 7.7 40.6 92.4 200.7 32.7 4.1 978.0 489.1 2745.6 Construct a frequence distribution for the combined cloud-seeding rain measurements. Use 6 bins. Class Frequency -250 < x < 250 250 < x < 750 750 < x < 1250 1250 < x < 1750 1750 < x < 2250 2250…arrow_forwardtate whether the investigation in question is an observational study or a designed experiment. Justify youranswer in each case. Heart Failure. In the paper “Cardiac-Resynchronization Therapy with or without an Implantable Debrillator in Advanced Chronic Heart Failure” (New England Journal of Medicine, Vol. 350, pp. 2140–2150), M. Bristow et al. reported the results of a study of methods for treating patients who had advanced heart failure due to ischemic or nonischemic cardiomyopathies. A total of 1520 patients were randomly assigned in a 1:2:2 ratio to receive optimal pharmacologic therapy alone or in combination with either a pacemaker or a pacemaker–debrillator combination. The patients werethen observed until they died or were hospitalized for any cause.arrow_forward
- Process 1 Process 2 Process 3 60 45 50 58 40 52 55 35 56 62 34 47 68 52 48 52 49 52 64 48 51 66 39 50 One-way ANOVA: Process 1, Process 2, Process 3 Source DF ss MS F P Treatment 2 1282.8 Error 21 578.9 Total 23 1861.7 A health food company wants to determine the best process for blanching dark green vegetable material so it can be added to other food products without losing vitamin A. They are examining three different blanching processes to determine which is best in terms of vitamin A retention (mg/100mg). The data collected and partial ANOVA results appears above. The F-statistic value is F = 27.57. O F = 2.215. O F = 23.267. F = 3.22.arrow_forwardAn article in the ASCE Journal of Energy Engineering [“Overview of Reservoir Release Improvements at 20 TVA Dams” (Vol. 125, April 1999, pp. 1–17)] presents data on dissolved oxygen concentrations in streams below 20 dams in the Tennessee Valley Authority system. The observations are (in milligrams per liter):arrow_forward& The accompanying table gives plasma epinephrine concentration for ten experimental subjects during (1) isoflurane, (2) halothane, and (3) cyclopropane anesthesia ("Sympathoadrenal and Hemodynamic Effects of Isoflurane, Halothane, and Cyclopropane in Dogs." Anesthesiology, 1974: 465-470). a. Does the choice of anesthetic affect true average concentration? Test H: a, = a, = a, = 0 at level .05 after constructing the ANOVA table. %3D Subject (B) 2 3 4 5 .51 1.00 .39 28 .39 29 Anesthetic 38 .21 2 .30 3 1.07 1.35 .63 (A) .69 .28 1.24 6. 7 8 10 33 17 .32 .56 1.02 .69 .32 .39 1 .36 Anesthetic 2 .88 51 .42 (A) 3 1.53 49 .30 ΣΣή-13.7980arrow_forward
- Wild irises are beautiful flowers found throughout the United States, Canada, and northern Europe. This problem concerns the length of the sepal (leaf-like part covering the flower) of different species of wild iris. Data are based on information taken from an article by R. A. Fisher in Annals of Eugenics (Vol. 7, part 2, pp. 179 -188). Measurements of sepal length in centimeters from random samples of Iris setosa (I), Iris versicolor (II), and Iris virginica (III) are as follows below. I II III 5.5 5.2 6.8 4.6 6.5 5.3 5.1 6.1 4.4 5.5 4.1 7.9 4.1 5.1 5.9 5.4 6.1 6.9 5.4 5.1 6.6 Shall we reject or not reject the claim that there are no differences among the population means of sepal length for the different species of iris? Use a 5% level of significance. (a) What is the level of significance?State the null and alternate hypotheses. Ho: ?1 = ?2 = ?3; H1: Exactly two means are equal.Ho: ?1 = ?2 = ?3; H1: Not all the means are equal. Ho: ?1 = ?2 = ?3; H1:…arrow_forwardWild irises are beautiful flowers found throughout the United States, Canada, and northern Europe. This problem concerns the length of the sepal (leaf-like part covering the flower) of different species of wild iris. Data are based on information taken from an article by R. A. Fisher in Annals of Eugenics (Vol. 7, part 2, pp. 179 -188). Measurements of sepal length in centimeters from random samples of Iris setosa (I), Iris versicolor (II), and Iris virginica (III) are as follows below. I II III 5.7 5.1 6.5 4.7 6.2 5.1 4.7 6.6 4.7 5.8 4.9 7.5 4.6 5.2 5.3 5.3 6.2 6.2 5.4 5.8 6.4 (b) Find SSTOT, SSBET, and SSW and check that SSTOT = SSBET + SSW. (Use 3 decimal places.) SSTOT = SSBET = SSW = Find d.f.BET, d.f.W, MSBET, and MSW. (Use 4 decimal places for MSBET, and MSW.) dfBET = dfW = MSBET = MSW = Find the value of the sample F statistic. (Use 2 decimal places.)What are the degrees of freedom? (numerator) (denominator)arrow_forwardWild irises are beautiful flowers found throughout the United States, Canada, and northern Europe. This problem concerns the length of the sepal (leaf-like part covering the flower) of different species of wild iris. Data are based on information taken from an article by R. A. Fisher in Annals of Eugenics (Vol. 7, part 2, pp. 179 -188). Measurements of sepal length in centimeters from random samples of Iris setosa (I), Iris versicolor (II), and Iris virginica (III) are as follows below. I II III 5.9 5.8 6.9 4.8 6.5 5.6 4.6 6.4 4.9 5.7 4.3 7.7 4.8 5.8 5.6 5.4 6.3 6.3 5.8 5.5 6.6 Shall we reject or not reject the claim that there are no differences among the population means of sepal length for the different species of iris? Use a 5% level of significance. (b) Find SSTOT, SSBET, and SSW and check that SSTOT = SSBET + SSW. (Use 3 decimal places.) SSTOT = SSBET = SSW = Find d.f.BET, d.f.W, MSBET, and MSW. (Use 4 decimal places for MSBET, and…arrow_forward
- MATLAB: An Introduction with ApplicationsStatisticsISBN:9781119256830Author:Amos GilatPublisher:John Wiley & Sons IncProbability and Statistics for Engineering and th...StatisticsISBN:9781305251809Author:Jay L. DevorePublisher:Cengage LearningStatistics 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:PEARSONThe Basic Practice of StatisticsStatisticsISBN:9781319042578Author:David S. Moore, William I. Notz, Michael A. FlignerPublisher:W. H. FreemanIntroduction to the Practice of StatisticsStatisticsISBN:9781319013387Author:David S. Moore, George P. McCabe, Bruce A. CraigPublisher:W. H. Freeman
![Text book image](https://www.bartleby.com/isbn_cover_images/9781119256830/9781119256830_smallCoverImage.gif)
![Text book image](https://www.bartleby.com/isbn_cover_images/9781305251809/9781305251809_smallCoverImage.gif)
![Text book image](https://www.bartleby.com/isbn_cover_images/9781305504912/9781305504912_smallCoverImage.gif)
![Text book image](https://www.bartleby.com/isbn_cover_images/9780134683416/9780134683416_smallCoverImage.gif)
![Text book image](https://www.bartleby.com/isbn_cover_images/9781319042578/9781319042578_smallCoverImage.gif)
![Text book image](https://www.bartleby.com/isbn_cover_images/9781319013387/9781319013387_smallCoverImage.gif)