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The effectiveness of antidepressants in treating the eating disorder bulimia was examined in the article “Bulimia Treated with Imipramine: A Placebo-Controlled Double-Blind Study” (American Journal of Psychology [1983]: 554–558). A group of patients diagnosed with bulimia were randomly assigned to one of two treatment groups, one receiving imipramine and the other a placebo. One of the variables recorded was binge frequency. The authors chose to analyze the data using a rank-sum test because it makes no assumption of normality. They stated that “because of the wide
Data on number of binges during one week that are consistent with the findings of the article are given in the following table:
Do these data strongly suggest that imipramine is effective in reducing the mean number of binges per week? Use a level 0.05 rank-sum test.
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Chapter 16 Solutions
Introduction to Statistics and Data Analysis
- A manufacturer of pens has hired an advertising agency to develop an advertising campaign for the upcoming holiday season. To prepare for this project, the research director decides to initiate a study of the effect of advertising on product perception. An experiment is designed to compare three different advertisements. Advertisement A greatly undersells the pen's characteristics. Advertisement B slightly undersells the pen's characteristics. Advertisement C slightly oversells the pen's characteristics. A sample of 18 adult respondents, taken from a larger focus group, is randomly assigned to the three advertisements (so that there are 6 respondents to each advertisement). After reading the advertisement and developing a sense of "product expectation," all respondents unknowingly receive the same pen to evaluate. The respondents are permitted to test the pen and the plausibility of the advertising copy. The respondents are then asked to rate the pen from 1 to 7 (lowest to highest) on…arrow_forwardA magazine reported on the "... treatment-emergent adverse events that occurred in 2% or more patients treated with a new medicine and with incidence greater than placebo in the treatment of depression, OCD, or bulimia." In the study, patients took the new medicine and patients were given placebo. Identify the a. treatment group, b. control group, and c. treatments.arrow_forwardResearchers recruited 1000 10- and 20-year-olds to participate in a study about age differences in aggression and the impact of violent video games on aggression. For 1-hour per day, half the participants were randomly assigned to play violent video games, while the other half played a nonviolent video game. A test for aggression was administered at the end of the year, and each participant received a score between 1 and 50 (higher scores indicate greater aggression). The results of the study are shown below: Factor 1 10 years 20 years old old Violent 35 25 Factor games 2 Nonviolent 25 45 games Is there a main effect of age? If so, which age shows more aggression?arrow_forward
- In a study of the adverse effects of x-rays among children, a retrospective cohort study was done using records from several large children's hospitals for the period of 1980 to 1985. 5,000 children were selected as a representative population of ill children seen at the hospitals during that time. Subjects were classified according to whether or not they received an x-ray during their stay in the hospital and were followed from their hospital stay through 2005 for the development of cancer. During the follow-up period, 30 incident cancers occurred in 3,000 children who had received an x-ray, and 5 incident cancers occurred in the 2,000 children who had not received an x-ray during their hospitalization. 1q. What are the rates of cancer incidence in each exposure group (per 1,000)? b.What is the attributable risk of cancer due to x-ray in this study population? 11c.. What is the risk ratio for the effect of exposure on the development of cancer in this study? What is the interpretation…arrow_forwardIn a study examining the effect of humor on interpersonal attractions, McGee and Shevlin (2009) found that a man's sense of humor had significant effect on how he was perceieved by woman. In the study, female college students were given brief descriptions of a po tential romantic partner and then rated the attractiveness of the male on a scale from 1 (low) to 7 (high). The fictitious male was described positively as being single , ambitious, and having good job prospects. In one dition, the description also said that he had a great sense of humor. The results showed that the description was rated significantly higher when "a sense of humor" was included. To further examine this effect, a researcher selected a sample of n = 16colle college males and asked them to read a brief description of a female and then rate the attractiveness of the woman in the description . The description had been used in previous research but was modified by adding a statement describing a good sense of humor…arrow_forwardIn a study examining the effect of humor on interpersonal attractions, McGee and Shevlin (2009) found that a man’s sense of humor had a significant effect on how he was perceived by women. In the study, female college students were given brief descriptions of a potential romantic partner and then rated the attractiveness of the male on a scale from 1 (low) to 7 (high). The fictitious male was described positively as being single, ambitious, and having good job prospects. In one condition, the description also said that he had a great sense of humor. The results showed that the description was rated significantly higher when “a sense of humor” was included. To examine this effect further, a researcher selected a sample of n = 16 college males and asked them to read a brief description of a female and then rate the attractiveness of the woman in the description. The description had been used in previous research but was modified by adding a statement describing a good sense of humor.…arrow_forward
- 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 8 10 9 9 14 11 11 17 13 13 16 15 7 16 12 Mean of X = 10 14 12 S^2 = 5.6 8.4 4 Using 5% of significance, test the hypothesis that the three groups differ in their effectiveness.arrow_forwardIn a study examining the effect of humor on interpersonal attractions, McGee and Shevlin (2009) found that a man’s sense of humor had a significant effect on how he was perceived by women. In the study, female college students were given brief descriptions of a potential romantic partner and then rated the attractiveness of the male on a scale from 1 (low) to 7 (high). The fictitious male was described positively as being single, ambitious, and having good job prospects. In one condition, the description also said that he had a great sense of humor. The results showed that the description was rated significantly higher when “a sense of humor” was included. To examine this effect further, a researcher selected a sample of n = 16 college males and asked them to read a brief description of a female and then rate the attractiveness of the woman in the description. The description had been used in previous research but was modified by adding a statement describing a good sense of humor.…arrow_forwardQ1: Placebo effect of exercise In a high-profile research study, Crum and Langer (2007) performed an experiment to test whether the relationship between physical exercise and health is impacted by one's mindset: in other words, if there is any "placebo effect" of exercise. A sample of 84 randomly selected hotel workers in the United States were placed either into a treatment group (n=44) or control group (n=40) depending on which hotel they worked at. The treatment group was given information demonstrating how their work is good physical exercise, while the control group was not given this information. They measured the body mass index (BMI) for each worker before the experiment and again four weeks after the experiment. a. Are the treatment group and control group independent of each other, and if so why? b. Now consider the treatment group alone: are the measurements of BMI taken before and after the experiment independent of each other, and if so why? c. What is the most appropriate…arrow_forward
- 1.2 Sinusitis and antibiotics, Part I. Researchers studying the effect of antibiotic treatment for acute sinusitis compared to symptomatic treatments randomly assigned 166 adults diagnosed with acute sinusitis to one of two groups: treatment or control. Study participants received either a 10-day course of amoxicillin (an antibiotic) or a placebo similar in appearance and taste. The placebo consisted of symptomatic treatments such as acetaminophen, nasal decongestants, etc. At the end of the 10-day period, patients were asked if they experienced improvement in symptoms. The distribution of responses is summarized below.³ Group Treatment Control Total Self-reported improvement in symptoms Yes 66 65 131 No 19 16 35 Total 85 81 166 (a) What percent of patients in the treatment group experienced improvement in symptoms? (b) What percent experienced improvement in symptoms in the control group? (c) In which group did a higher percentage of patients experience improvement in symptoms? (d)…arrow_forwardKava is a beverage or extract that is made from Piper methysticum, a plant native to the western Pacific islands. Suppose that, in a randomized comparative experiment to determine if taking kava daily can reduce insomnia, a group of participants with insomnia were randomly assigned to take kava (treatment group) or a placebo (control group). After six weeks, the participants were interviewed to see if they experienced a decrease in insomnia. The table shows the results from the sample. The counts are the number of people in each group who experienced a decrease in insomnia. Group Description Population proportion Sample size Sample count Sample proportion 1 Treatment (kava) P1 n₁ = 402 x1 = 213 P₁ = 0.5299 2 Control (placebo) P2 n₂ = 521 x₂ = 121 P2 = 0.2322 Compute the standard error estimate, SE, of the difference in the sample proportions. Give your answer to at least four decimal places. 0.0438 SE = Incorrect Determine the value of the two-sample z-statistic for the difference in…arrow_forwardQuit Smoking: The New England Journal of Medicine published the results of a double-blind, placebo-controlled experiment to study the effect of nicotine patches and the antidepressant bupropion on quitting smoking. The target for quitting smoking was the 8th day of the experiment. In this experiment researchers randomly assigned smokers to treatments. The following is an excerpt from this same study. “ A total of 311 subjects (34.8 percent) discontinued one or both medications. Seventy-nine subjects stopped treatment because of adverse events: 6 in the placebo group (3.8 percent), 16 in the nicotine-patch group (6.6 percent), 29 in the bupropion group (11.9 percent), and 28 in the combined treatment group (11.4 percent). The most common adverse events were insomnia and headache.” Recall that 160 smokers took the placebo and 244 smokers used nicotine patches. Could the researcher use this data with an inference procedure from this module to test a claim about (or to estimate the…arrow_forward
- Holt Mcdougal Larson Pre-algebra: Student Edition...AlgebraISBN:9780547587776Author:HOLT MCDOUGALPublisher:HOLT MCDOUGAL
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