Introduction to Statistics and Data Analysis
5th Edition
ISBN: 9781305750999
Author: Peck Olson Devore
Publisher: CENGAGE C
expand_more
expand_more
format_list_bulleted
Videos
Textbook Question
Chapter 2.4, Problem 51E
Swedish researchers concluded that viewing and discussing art soothes the soul and helps relieve medical conditions such as high blood pressure and constipation (AFP International News Agency, October 14, 2005). This conclusion was based on a study in which 20 elderly women gathered once a week to discuss different works of art. The study also included a control group of 20 elderly women who met once a week to discuss their hobbies and interests. At the end of 4 months, the art discussion group was found to have a more positive attitude, to have lower blood pressure, and to use fewer laxatives than the control group.
- a. Why would it be important to determine if the researchers randomly assigned the women participating in the study to one of the two groups?
- b. Explain why you think that the researchers included a control group in this study.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
Question 2
A nickel-titanium alloy is used to make components for jet turbine aircraft engines. Cracking is a potentially
serious problem in the final part because it can lead to nonrecoverable failure. A test is run at the parts producer
to determine the effect of four factors on cracks. The four factors are: pouring temperature (A), titanium content
(B), heat treatment method (C), amount of grain refiner used (D). Two replicates of a 24 design are run, and
the length of crack (in mm x10-2) induced in a sample coupon subjected to a standard test is measured. The
data are shown in Table 2.
1
(a) Estimate the factor effects. Which factor effects appear to be large?
(b) Conduct an analysis of variance. Do any of the factors affect cracking? Use a = 0.05.
(c) Write down a regression model that can be used to predict crack length as a function of the significant
main effects and interactions you have identified in part (b).
(d) Analyze the residuals from this experiment.
(e) Is there an…
A 24-1 design has been used to investigate the effect of four factors on the resistivity of a silicon wafer. The data
from this experiment are shown in Table 4.
Table 4: Resistivity Experiment for Exercise 5
Run
A
B
с
D
Resistivity
1
23
2
3
4
5
6
7
8
9
10
11
12
I+I+I+I+Oooo
0
0
||++TI++o000
33.2
4.6
31.2
9.6
40.6
162.4
39.4
158.6
63.4
62.6
58.7
0
0
60.9
3
(a) Estimate the factor effects. Plot the effect estimates on a normal probability scale.
(b) Identify a tentative model for this process. Fit the model and test for curvature.
(c) Plot the residuals from the model in part (b) versus the predicted resistivity. Is there any indication on
this plot of model inadequacy?
(d) Construct a normal probability plot of the residuals. Is there any reason to doubt the validity of the
normality assumption?
Stem1: 1,4
Stem 2: 2,4,8
Stem3: 2,4
Stem4: 0,1,6,8
Stem5: 0,1,2,3,9
Stem 6: 2,2
What’s the Min,Q1, Med,Q3,Max?
Chapter 2 Solutions
Introduction to Statistics and Data Analysis
Ch. 2.1 - The article How Dangerous Is a Day in the...Ch. 2.1 - The authors of the paper Fudging the Numbers:...Ch. 2.1 - The article Why We Fall for This (AARP Magazine,...Ch. 2.1 - The article “Television’s Value to Kids: It’s All...Ch. 2.1 - The article Acupuncture for Bad Backs: Even Sham...Ch. 2.1 - The article Display of Health Risk Behaviors on...Ch. 2.1 - Can choosing the right music make wine taste...Ch. 2.1 - Fruit Juice May Be Fueling Pudgy Preschoolers,...Ch. 2.1 - The article Americans are Getting the Wrong Idea...Ch. 2.1 - Based on a survey conducted on the eDiets.com web...
Ch. 2.1 - A survey of affluent Americans (those with incomes...Ch. 2.1 - Does living in the South cause high blood...Ch. 2.2 - A New York psychologist recommends that if you...Ch. 2.2 - As part of a curriculum review, a psychology...Ch. 2.2 - A petition with 500 signatures is submitted to a...Ch. 2.2 - The article Bicyclists and Other Cyclists (Annals...Ch. 2.2 - The article Teenage Physical Activity Reduces Risk...Ch. 2.2 - For each of the situations described, state...Ch. 2.2 - Of the 6500 students enrolled at a community...Ch. 2.2 - Briefly explain why it is advisable to avoid the...Ch. 2.2 - The chairman of a California ballot initiative...Ch. 2.2 - The authors of the paper Digital Inequality:...Ch. 2.2 - The 2013 National Study of Substance Use Habits of...Ch. 2.2 - The paper Deception and Design: The Impact of...Ch. 2.2 - The authors of the paper “Popular Video Games:...Ch. 2.2 - Participants in a study of honesty in online...Ch. 2.2 - The report “Undergraduate Students and Credit...Ch. 2.2 - The financial aid advisor of a university plans to...Ch. 2.2 - Suppose that you were asked to help design a...Ch. 2.2 - The article High Levels of Mercury Are Found in...Ch. 2.2 - Whether or not to continue a Mardi Gras Parade...Ch. 2.3 - The head of the quality control department at a...Ch. 2.3 - A study of college students showed a temporary...Ch. 2.3 - According to the article Rubbing Hands Together...Ch. 2.3 - The following is from an article titled After the...Ch. 2.3 - The report Comparative Study of Two Computer Mouse...Ch. 2.3 - The Institute of Psychiatry at Kings College...Ch. 2.3 - In an experiment to compare two different surgical...Ch. 2.3 - In many digital environments, users are allowed to...Ch. 2.3 - Does playing action video games provide more than...Ch. 2.3 - Prob. 42ECh. 2.3 - Construct a diagram to represent the gasoline...Ch. 2.3 - An advertisement for a sweatshirt that appeared in...Ch. 2.3 - The paper Turning to Learn: Screen Orientation and...Ch. 2.3 - Prob. 46ECh. 2.3 - Red wine contains flavonol, an antioxidant thought...Ch. 2.4 - Explain why some studies include both a control...Ch. 2.4 - Explain why blinding is a reasonable strategy in...Ch. 2.4 - Give an example of an experiment for each of the...Ch. 2.4 - Swedish researchers concluded that viewing and...Ch. 2.4 - In an experiment to compare two different surgical...Ch. 2.4 - The article Placebos Are Getting More Effective....Ch. 2.4 - The article Yes That Miley Cyrus Biography Helps...Ch. 2.4 - Suppose that the researchers who carried out the...Ch. 2.4 - The article Doctor Dogs Diagnose Cancer by...Ch. 2.4 - Pismo Beach, California, has an annual clam...Ch. 2.4 - The San Luis Obispo Tribune (May 7, 2002) reported...Ch. 2.4 - The article A Debate in the Dentists Chair (San...Ch. 2.5 - The article “Effects of Too Much TV Can Be Undone”...Ch. 2 - The article Rethinking Calcium Supplements (US...Ch. 2 - A pollster for the Public Policy Institute of...Ch. 2 - A study in Florida is examining whether health...Ch. 2 - Is status related to a student’s understanding of...Ch. 2 - The article “Tots’ TV-Watching May Spur Attention...Ch. 2 - A study of more than 50,000 U.S. nurses found that...Ch. 2 - Prob. 71CRCh. 2 - The article Workers Grow More Dissatisfied in the...Ch. 2 - According to the article “Effect of Preparation...Ch. 2 - Prob. 74CRCh. 2 - Prob. 75CRCh. 2 - Researchers at the University of Houston decided...Ch. 2 - You have been asked to determine on what types of...Ch. 2 - A manufacturer of clay roofing tiles would like to...Ch. 2 - A mortgage lender routinely places advertisements...Ch. 2 - A tropical forest survey conducted by Conservation...
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
- Are the t-statistics here greater than 1.96? What do you conclude? colgPA= 1.39+0.412 hsGPA (.33) (0.094) Find the P valuearrow_forwardA poll before the elections showed that in a given sample 79% of people vote for candidate C. How many people should be interviewed so that the pollsters can be 99% sure that from 75% to 83% of the population will vote for candidate C? Round your answer to the whole number.arrow_forwardSuppose a random sample of 459 married couples found that 307 had two or more personality preferences in common. In another random sample of 471 married couples, it was found that only 31 had no preferences in common. Let p1 be the population proportion of all married couples who have two or more personality preferences in common. Let p2 be the population proportion of all married couples who have no personality preferences in common. Find a95% confidence interval for . Round your answer to three decimal places.arrow_forward
- A history teacher interviewed a random sample of 80 students about their preferences in learning activities outside of school and whether they are considering watching a historical movie at the cinema. 69 answered that they would like to go to the cinema. Let p represent the proportion of students who want to watch a historical movie. Determine the maximal margin of error. Use α = 0.05. Round your answer to three decimal places. arrow_forwardA random sample of medical files is used to estimate the proportion p of all people who have blood type B. If you have no preliminary estimate for p, how many medical files should you include in a random sample in order to be 99% sure that the point estimate will be within a distance of 0.07 from p? Round your answer to the next higher whole number.arrow_forwardA clinical study is designed to assess the average length of hospital stay of patients who underwent surgery. A preliminary study of a random sample of 70 surgery patients’ records showed that the standard deviation of the lengths of stay of all surgery patients is 7.5 days. How large should a sample to estimate the desired mean to within 1 day at 95% confidence? Round your answer to the whole number.arrow_forward
- A clinical study is designed to assess the average length of hospital stay of patients who underwent surgery. A preliminary study of a random sample of 70 surgery patients’ records showed that the standard deviation of the lengths of stay of all surgery patients is 7.5 days. How large should a sample to estimate the desired mean to within 1 day at 95% confidence? Round your answer to the whole number.arrow_forwardIn the experiment a sample of subjects is drawn of people who have an elbow surgery. Each of the people included in the sample was interviewed about their health status and measurements were taken before and after surgery. Are the measurements before and after the operation independent or dependent samples?arrow_forwardiid 1. The CLT provides an approximate sampling distribution for the arithmetic average Ỹ of a random sample Y₁, . . ., Yn f(y). The parameters of the approximate sampling distribution depend on the mean and variance of the underlying random variables (i.e., the population mean and variance). The approximation can be written to emphasize this, using the expec- tation and variance of one of the random variables in the sample instead of the parameters μ, 02: YNEY, · (1 (EY,, varyi n For the following population distributions f, write the approximate distribution of the sample mean. (a) Exponential with rate ẞ: f(y) = ß exp{−ßy} 1 (b) Chi-square with degrees of freedom: f(y) = ( 4 ) 2 y = exp { — ½/ } г( (c) Poisson with rate λ: P(Y = y) = exp(-\} > y! y²arrow_forward
- 2. Let Y₁,……., Y be a random sample with common mean μ and common variance σ². Use the CLT to write an expression approximating the CDF P(Ỹ ≤ x) in terms of µ, σ² and n, and the standard normal CDF Fz(·).arrow_forwardmatharrow_forwardCompute the median of the following data. 32, 41, 36, 42, 29, 30, 40, 22, 25, 37arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Big Ideas Math A Bridge To Success Algebra 1: Stu...AlgebraISBN:9781680331141Author:HOUGHTON MIFFLIN HARCOURTPublisher:Houghton Mifflin Harcourt
Glencoe Algebra 1, Student Edition, 9780079039897...AlgebraISBN:9780079039897Author:CarterPublisher:McGraw Hill
College Algebra (MindTap Course List)AlgebraISBN:9781305652231Author:R. David Gustafson, Jeff HughesPublisher:Cengage Learning
Holt Mcdougal Larson Pre-algebra: Student Edition...AlgebraISBN:9780547587776Author:HOLT MCDOUGALPublisher:HOLT MCDOUGAL
Big Ideas Math A Bridge To Success Algebra 1: Stu...
Algebra
ISBN:9781680331141
Author:HOUGHTON MIFFLIN HARCOURT
Publisher:Houghton Mifflin Harcourt
Glencoe Algebra 1, Student Edition, 9780079039897...
Algebra
ISBN:9780079039897
Author:Carter
Publisher:McGraw Hill
College Algebra (MindTap Course List)
Algebra
ISBN:9781305652231
Author:R. David Gustafson, Jeff Hughes
Publisher:Cengage Learning
Holt Mcdougal Larson Pre-algebra: Student Edition...
Algebra
ISBN:9780547587776
Author:HOLT MCDOUGAL
Publisher:HOLT MCDOUGAL
What Are Research Ethics?; Author: HighSchoolScience101;https://www.youtube.com/watch?v=nX4c3V23DZI;License: Standard YouTube License, CC-BY
What is Ethics in Research - ethics in research (research ethics); Author: Chee-Onn Leong;https://www.youtube.com/watch?v=W8Vk0sXtMGU;License: Standard YouTube License, CC-BY