Intro Stats
4th Edition
ISBN: 9780321826275
Author: Richard D. De Veaux
Publisher: PEARSON
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Textbook Question
Chapter 11, Problem 48E
Contrast baths Contrast bath treatments use the immersion of an injured limb alternately in water of two contrasting temperatures. Those who use the method claim that it can reduce swelling. Researchers compared three treatments: (1) contrast baths and exercise, (2) contrast baths alone, and (3) exercise alone. (R. G. Janssen, D. A. Schwartz, and P. F. Velleman, “A Randomized Controlled Study of Contrast Baths on Patients with Carpal Tunnel Syndrome,” Journal of Hand Therapy, 2009) They report the following boxplots comparing the change in hand volume after treatment:
- a) The researchers conclude that the differences were not statistically significant. Explain what that means in context.
- b) The title says that the study was randomized and controlled. Explain what that probably means for this study.
- c) The study did not use a placebo treatment. What was done instead? Do you think that was an appropriate choice? Explain.
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ANOVA Table
Source DFSum ofSquaresMeanSquare F-Ratio P-ValueType 1 6.31 6.31 0.7673 0.3874Error 33 271.47 8.22Total 34 2.77Means and Std DeviationsLevel n Mean StdDevStandard 18 81.5556 3.2166Octel 17 80.7059 2.43708a) What are the null and alternative hypotheses?b) What do you conclude from the ANOVA table?c) Do the assumptions for the test seem to be reasonable?d) Perform a two-sample pooled t-test of the difference.What P-value do you get? Show that the square of thet-statistic is the same (to rounding error) as the F-ratio.
(OPHTHALMOLOGY) The following data are from a study on Botox injections. Patients received a high-dose injection in one eye (experimental treatment = treatment E) and a low-dose injection in the other eye (control treatment = treatment C). Patients were asked to rate the level of pain in each eye on a 1–10 scale, with higher scores indicating more pain. The assignment of treatments to eyes was randomized. The subjects came back over several visits. Data from the last visit are given in the following table:
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5. What is the correct decision based on the p-value or critical value method?
Chapter 11 Solutions
Intro Stats
Ch. 11.3 - At one time, a method called gastric freezing was...Ch. 11.4 - Recall the experiment about gastric freezing, an...Ch. 11 - Steroids The 1990s and early 2000s could be...Ch. 11 - Prob. 2ECh. 11 - Prob. 3ECh. 11 - Tomatoes You want to compare the tastiness and...Ch. 11 - Tips II For the experiment described in Exercise...Ch. 11 - Prob. 6ECh. 11 - Prob. 7ECh. 11 - Prob. 8E
Ch. 11 - Prob. 9ECh. 11 - Prob. 10ECh. 11 - Block that tip The driver of Exercise 3 wants to...Ch. 11 - Blocking tomatoes To obtain enough plants for the...Ch. 11 - Prob. 13ECh. 11 - Prob. 14ECh. 11 - Standardized test scores For his statistics class...Ch. 11 - Heart attacks and height Researchers who examined...Ch. 11 - Prob. 17ECh. 11 - Prob. 18ECh. 11 - Menopause Researchers studied the herb black...Ch. 11 - Honesty Coffee stations in offices often just ask...Ch. 11 - 2134. Whats the design? Read each brief report of...Ch. 11 - 2134. Whats the design? Read each brief report of...Ch. 11 - 2134. Whats the design? Read each brief report of...Ch. 11 - 2134. Whats the design? Read each brief report of...Ch. 11 - 2134. Whats the design? Read each brief report of...Ch. 11 - 2134. Whats the design? Read each brief report of...Ch. 11 - 2134. Whats the design? Read each brief report of...Ch. 11 - 2134. Whats the design? Read each brief report of...Ch. 11 - 2134. Whats the design? Read each brief report of...Ch. 11 - 2134. Whats the design? Read each brief report of...Ch. 11 - 2134. Whats the design? Read each brief report of...Ch. 11 - 2134. Whats the design? Read each brief report of...Ch. 11 - 2134. Whats the design? Read each brief report of...Ch. 11 - 2134. Whats the design? Read each brief report of...Ch. 11 - Omega-3 Exercise 21 describes an experiment that...Ch. 11 - Insomnia Exercise 24 describes an experiment...Ch. 11 - Omega-3, revisited Exercises 21 and 35 describe an...Ch. 11 - Insomnia, again Exercises 24 and 36 describe an...Ch. 11 - Omega-3, finis Exercises 21, 35, and 37 describe...Ch. 11 - Insomnia, at last Exercises 24, 36, and 38...Ch. 11 - Injuries Exercise 33 describes an experiment that...Ch. 11 - Tomatoes II Describe a strategy to randomly split...Ch. 11 - Shoes A running-shoe manufacturer wants to test...Ch. 11 - Swimsuits A swimsuit manufacturer wants to test...Ch. 11 - Hamstrings Exercise 33 discussed an experiment to...Ch. 11 - Diet and blood pressure An experiment showed that...Ch. 11 - Mozart Will listening to a Mozart piano sonata...Ch. 11 - Contrast baths Contrast bath treatments use the...Ch. 11 - Prob. 49ECh. 11 - Swimming Recently, a group of adults who swim...Ch. 11 - Dowsing Before drilling for water, many rural...Ch. 11 - Healing A medical researcher suspects that giving...Ch. 11 - Reading Some schools teach reading using phonics...Ch. 11 - Gas mileage Do cars get better gas mileage with...Ch. 11 - Weekend deaths A study published in the New...Ch. 11 - Shingles A research doctor has discovered a new...Ch. 11 - Beetles Hoping to learn how to control crop damage...Ch. 11 - SAT prep Can special study courses actually help...Ch. 11 - Safety switch An industrial machine requires an...Ch. 11 - Washing clothes A consumer group wants to test the...Ch. 11 - Skydiving, anyone? A humor piece published in the...
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