Statistics: The Art and Science of Learning from Data (4th Edition)
4th Edition
ISBN: 9780321997838
Author: Alan Agresti, Christine A. Franklin, Bernhard Klingenberg
Publisher: PEARSON
expand_more
expand_more
format_list_bulleted
Videos
Textbook Question
Chapter 14.3, Problem 23PB
Reducing cholesterol An experiment randomly assigns 100 subjects suffering from high cholesterol to one of four groups: low-dose Lipitor, high-dose Lipitor, low-dose Zocor, high-dose Zocor. After three months of treatment, the change in cholesterol level is measured.
- a. Identify the response variable and the two factors.
- b. What are four treatments that can be compared with this experiment?
- c. What comparisons are relevant when we control for dose level?
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
3. A researcher was interested in the effects of a drug on depression. Subjects were randomly
assigned to one of the three groups. Subjects in the control group received a placebo and the
subjects in the two treatment groups received either a 0.2 mg or a 0.4 mg dosage of the drug.
After several weeks of drug (or placebo) treatment, the researcher measured the subjects' level
of depression (a low score indicating greater depression) The following data were obtained.
Placebo
0.2 mg
0.4 mg
12
11
12
10
9.
14
11
11
17
13
13
16
15
7
16
12
Mean of X = 10
14
12
S^2 = 5.6
8.4
Using 5% of significance, test the hypothesis that the three groups differ in their effectiveness.
Indicate whether the study described is an observational study or a controlled experiment.A group of students is divided into two groups. One group is a given a new chewable vitamin and the other group is given a placebo. After six months they are asked to fill out a questionnaire and given a health exam to see whether the new vitamin has health benefits that are better than a placebo.
Observational study
Controlled experiment
A researcher conducts an independent-measures study examining how the brain chemical serotonin is related to aggression. One sample of rats serves as a control group and receives a placebo that does not affect normal levels of serotonin. A second sample of rats receives a drug that lowers brain levels of serotonin. Then the researcher tests the animals by recording the number of aggressive responses each of the rats display. The data are as follows.
Control Low Serotonin
n = 10 n = 15
M = 14 M = 19
SS = 180.5 SS = 130.0
A. Does the drug have a significant effect on aggression?Use an alpha level of .05, two
tails.
H0 = ________________________________________
df = _________________________________________
tcritical =…
Chapter 14 Solutions
Statistics: The Art and Science of Learning from Data (4th Edition)
Ch. 14.1 - Hotel satisfaction The CEO of a company that owns...Ch. 14.1 - Prob. 2PBCh. 14.1 - Whats the best way to learn French? The following...Ch. 14.1 - Prob. 4PBCh. 14.1 - Prob. 5PBCh. 14.1 - ANOVA and box plots For two studies, each...Ch. 14.1 - Prob. 7PBCh. 14.1 - Smoking and personality A study about smoking and...Ch. 14.1 - Prob. 9PBCh. 14.1 - Prob. 10PB
Ch. 14.1 - Prob. 11PBCh. 14.2 - House prices and age For the House Selling Prices...Ch. 14.2 - Time on Facebook Do freshmen spent significantly...Ch. 14.2 - Prob. 14PBCh. 14.2 - Tukey holding time comparisons Refer to the...Ch. 14.2 - Prob. 16PBCh. 14.2 - REM regression Refer to the previous exercise. a....Ch. 14.2 - Prob. 18PBCh. 14.2 - Regression for outsourcing Refer to the previous...Ch. 14.2 - Advertising effect oil sales Each of 100...Ch. 14.3 - Reducing cholesterol An experiment randomly...Ch. 14.3 - Prob. 24PBCh. 14.3 - Political ideology in 2014 The GSS measures...Ch. 14.3 - Prob. 26PBCh. 14.3 - Corn and manure In Example 10, the coefficient of...Ch. 14.3 - Prob. 28PBCh. 14.3 - Regression for telephone holding times Refer to...Ch. 14.3 - Prob. 30PBCh. 14.3 - Income by gender and degree In 2012, the...Ch. 14.3 - Prob. 32PBCh. 14.3 - Attractiveness and getting dates The results in...Ch. 14.3 - Prob. 34PBCh. 14.3 - Regression of weight gain on diet Refer to the...Ch. 14 - Good friends and marital status Is the number of...Ch. 14 - Prob. 37CPCh. 14 - Singles watch more TV The 2014 General Social...Ch. 14 - Prob. 39CPCh. 14 - Prob. 40CPCh. 14 - Prob. 41CPCh. 14 - Prob. 42CPCh. 14 - Prob. 43CPCh. 14 - Comparing therapies for anorexia The Anorexia data...Ch. 14 - Prob. 45CPCh. 14 - Prob. 46CPCh. 14 - Prob. 47CPCh. 14 - Prob. 48CPCh. 14 - Prob. 49CPCh. 14 - Prob. 50CPCh. 14 - Prob. 51CPCh. 14 - TV watching by gender and race When we use the...Ch. 14 - Prob. 53CPCh. 14 - Prob. 54CPCh. 14 - Prob. 55CPCh. 14 - Prob. 56CPCh. 14 - Prob. 57CPCh. 14 - Prob. 59CPCh. 14 - Prob. 60CPCh. 14 - Prob. 61CPCh. 14 - Prob. 62CPCh. 14 - Prob. 63CPCh. 14 - Prob. 64CPCh. 14 - Prob. 65CPCh. 14 - Prob. 66CPCh. 14 - Prob. 67CPCh. 14 - Prob. 68CPCh. 14 - Prob. 69CPCh. 14 - Prob. 70CPCh. 14 - Prob. 71CP
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
- What is meant by the sample space of an experiment?arrow_forwardWhat is an experiment?arrow_forwardA researcher conducts an independent-measures study examining how the brain chemical serotonin is related to aggression. One sample of rats serves as a control group and receives a placebo that does not affect normal levels of serotonin. A second sample of rats receives a drug that lowers brain levels of serotonin. Then the researcher tests the animals by recording the number of aggressive responses each of the rats display. The data are as follows. Control Low Serotonin n = 15 n = 20 M = 18 M = 22 SS = 172.5 SS = 135.0 a. What research design was used to answer this question? b. What was the scale of measurement for the dependent variable? c. What was the scale of measurement for the independent variable? d. Does the drug have a significant effect on aggression? Use an alpha level of .05, two tails. e. Compute r2 and write an…arrow_forward
- Help please!!arrow_forwardWhat type of study is this? A first-year university unit wanted to give option of online teaching to determine whether online teaching improved learning outcomes. Students were allowed to enrol into online or on-campus classes. Grades at the end of semester were compared. Select one: O Experimental O Something else O Observationalarrow_forwardTreatment for depression: Researchers conducted a study of 18 patients whose depression had not responded to treatment (Zarate, 2006). Half received one intravenous dose of ketamine, hypothesized quick fix for depression; half received one intravenous dose of placebo. Far more of the patients who received ketamine improved, as measured by the Hamilton Depression Rating Scale, usually in less than 2 hours, than patients on placebo. a.What is the population of interest, and what is the sample in the study? b. Was random selection likely used? Explain your answer. c. Was random assignment likely used? Explain your answer. d. What is the independent variable and what are the levels? What is the dependent variable? e. What is the null hypothesis and what is the research hypothesis? f. What decision did the researchers make? (Respond using the language of inferential statistics.) g. If the researchers were incorrect in their decision, what kind of error did they make? Explain your answer.…arrow_forward
- In a certain study, the effect on oat yield was compared for the Pallinup, Overberg and Magnifico varieties of oats and four different concentrations of manure (0, 0.2, 0.4 and 0.6 tonnes per acre). Identify the experimental units, response variable, factor(s), levels of each factor and treatments.arrow_forwardResearchers studied 208 infants whose brains were temporarily deprived of oxygen due to complications at birth. When researchers detected oxygen deprivation, they randomly assigned babies to either usual care or to a whole-body cooling group. The goal was to see whether reducing body temperature for three days after birth increased the rate of survival without brain damage. What is the explanatory variable? A. Survival without brain damage B.Infants whose brains are temporarily deprived of oxygen C. Usual care or whole-body coolingarrow_forwardA study was done to compare the lung capacity of coal miners to the lung capacity of farm workers. The researcher studied 200 workers of each type. Other factors that might affect lung capacity are smoking habits and exercise habits. The smoking habits of the two worker types are similar, but the coal miners generally exercise less than the farm workers. Which of the following is the explanatory variable in this study? a. Exercise b. Lung capacity c. Smoking or not d. Occupation Which is the following classifications of variable types is false? a. customer satisfactory: very unsatisfied, unsatisfied, satisfied, very satisfied ---> ordinal categorical b. whether a student has previously taken a statistic course ---> categorical c. student height ---> continuous numerical d. Population of each state in the U.S. ---> continuous numericalarrow_forward
- A child psychologist believe that controlled physical outbursts of anger (like punching a pillow) may improve the mood of young boys with emotional impairment. He believes that the proportion of boys who benefit from the treatment is greater than the proportion of girls. A random sample from each population receives counseling in the treatment and is asked about their mood after an episode (x is the number of test subjects that reported an improvement in mood). The results of the study are summarized in the table below. Boys n1 = 200 Girls n2 = 210 %3D %3D X1 = 35 X2 = 28 Blank #1: Find the two sample proportions, reporting each as a decimal, rounded to two decimal places. Do the initial (untested) findings show what the researcher expected? Enter your answer as a list of 3 items: P1, P2, yes or no. Do not add any extra spaces and pay attention to rounding. For example, a valid answer may look like .52,.14,yes or .25,.50,no. Untested, you compared them but you could have done that…arrow_forwardA researcher examined the effects of mindfulness meditation on stress reduction. The researcher recruited n=9 participants from a university campus and asked them to participate in a 30-minute mindfulness med- itation session every day for two weeks. Before and after the two-week intervention period, the participants completed the Perceived Stress Scale, a standardized self-report measure of stress levels. The participants' stress scores are shown in this table. participant before meditation after meditation 1 15 13 2 19 3 9 4 11 5 11 6 14 10 7 16 16 8 17 18 9 21 17 33752687 13 13 On average, by how much did the anxiety scores change from before versus after the two weeks of meditation sessions? Use a related-samples t-test to determine if this change is statistically significant, and calculate the coefficient of determination r². Report your findings as a sentence or two that could be in the Results section of an APA-style research article.arrow_forwardWhich research design studies only people who are initially free of the disease of interest? Explain how this study design is different from the rest of the research designs a. Case control b. Cohort c. Cross sectional d. Experimentalarrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Glencoe Algebra 1, Student Edition, 9780079039897...AlgebraISBN:9780079039897Author:CarterPublisher:McGraw Hill
Big Ideas Math A Bridge To Success Algebra 1: Stu...AlgebraISBN:9781680331141Author:HOUGHTON MIFFLIN HARCOURTPublisher:Houghton Mifflin Harcourt
Holt Mcdougal Larson Pre-algebra: Student Edition...AlgebraISBN:9780547587776Author:HOLT MCDOUGALPublisher:HOLT MCDOUGAL
College Algebra (MindTap Course List)AlgebraISBN:9781305652231Author:R. David Gustafson, Jeff HughesPublisher:Cengage Learning
Glencoe Algebra 1, Student Edition, 9780079039897...
Algebra
ISBN:9780079039897
Author:Carter
Publisher:McGraw Hill
Big Ideas Math A Bridge To Success Algebra 1: Stu...
Algebra
ISBN:9781680331141
Author:HOUGHTON MIFFLIN HARCOURT
Publisher:Houghton Mifflin Harcourt
Holt Mcdougal Larson Pre-algebra: Student Edition...
Algebra
ISBN:9780547587776
Author:HOLT MCDOUGAL
Publisher:HOLT MCDOUGAL
College Algebra (MindTap Course List)
Algebra
ISBN:9781305652231
Author:R. David Gustafson, Jeff Hughes
Publisher:Cengage Learning
Introduction to experimental design and analysis of variance (ANOVA); Author: Dr. Bharatendra Rai;https://www.youtube.com/watch?v=vSFo1MwLoxU;License: Standard YouTube License, CC-BY