Concept explainers
The authors of the paper “Fudging the Numbers: Distributing Chocolate Influences Student Evaluations of an Undergraduate Course” (Teaching in Psychology [2007]: 245–247) carried out a study to see if
The researchers concluded that “Overall, students offered chocolate gave more positive evaluations than students not offered chocolate.” Indicate whether the study is an observational study or an experiment. Give a brief explanation for your choice.
Trending nowThis is a popular solution!
Chapter 2 Solutions
Introduction to Statistics and Data Analysis
- List the sample space of each experiment. Picking a one-digit numberarrow_forwardSeattle Grace Medical Center. As part of a long-term study of individuals 65 years of age or older, doctors at the Seattle Grace Medical Center in Washington state investigated the relationship between state of residence and depression. A sample of 60 individuals, all in reasonably good health, was selected; 20 individuals were residents of Texas, 20 were residents of Washington state, and 20 were residents of South Carolina. Each of the individuals sampled was given a standardized test to measure depression. The data collected follow; higher test scores indicate higher levels of depression. These data are contained in the attached data file SeattleGrace1. A second part of the study considered the relationship between state of residence and depression for individuals 65 years of age or older who had a chronic health condition such as diabetes and/or high blood pressure. A sample of 60 individuals with such conditions was identified. Again, 20 were residents of Texas, 20 were residents…arrow_forwardBinge drinking on college campuses has been a hot topic in the popular media and in scholarly research. Flett, Goldstein, Wall, Hewitt, Wekerle, and Azzi (2008) report the results of a study relating perfectionism to binge drinking. In the study, students were classified into three groups based on the number of binge drinking episodes they experienced during the past month (0, 1, 2 or more). The students then completed a perfectionism questionnaire including one scale measuring parental criticism. One sample item is “I never felt that I could meet my parents’ standards.” Students rated their level of agreement with each item, and the total score was calculated for each student. The following results are similar to those obtained by the researchers. Binge Drinking Episodes in Past Month 0 1 2 or more 8 10 13 N = 15 8 12 14 G = 165 10 8 12 ΣX2 = 1909 9 9 15 10 11…arrow_forward
- A Bloomberg Businessweek subscriber study asked, "In the past 12 months, when traveling for business, what type of airline ticket did you purchase most often?" A second question asked if the type of flight was domestic or international travel. Sample data obtained are shown in the following table. Type of Flight Type of Ticket First Class Business Class I Ho: Type of ticket purchased is independent of the type of flight Ha: Type of ticket purchased is not independent of the type of flight Compute the value of the X² test statistic (to 2 decimals).. Domestic 29 95 International 22 Economy Class 518 135 a. Using a 0.05 level of significance, is the type of ticket purchased independent of the type of flight? 121 Hint(s) Check My Work Use Table 3 of Appendix B to find the p-value. The p-value is less than 0.005 What is your conclusion? Conclude that the type of ticket purchased depends on the type of flight. b. Discuss any dependence that exists between the type of ticket and type of…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_forwardA survey of employees at a large financial organisation was conducted to determine the overall sentiment towards various aspects of how the company operates. 30 randomly selected departments in the organisation participated in the study. Every employee in these 30 randomly selected departments filled in a questionnaire, and the data were aggregated to calculate the following two variables of interest: Rating ComplaintsThe percentage of favourable responses (in each department) to how the company handles employee complaints Source: Chatterjee, S. and Price, B. (1977) Regression Analysis by Example. New York: Wiley. (Section 3.7, p.68ff of 2nd ed. (1991).) A simple linear regression was conducted. A scatter plot of Rating versus Complaints is shown in Figure 1 and the results of the regression analysis are shown in Table 1. Rating 80 o 70 60 The percentage of favourable responses (in each department) to the overall running of the company. 50 40 Model 1 40 Figure 1: Rating versus…arrow_forward
- The Health Behaviour in School-Aged Children (HSBC) network collects data on various behaviors of preteen and teenage children. In 2006, the HSBC network surveyed a randomly selected sample of 638 preteen and teenage boys in Greenland to determine what proportion of students were bullied at least twice per month in the previous few months. In the sample, 147 students were bullied at least twice per month, and 491 students were bullied less than twice per month. The HSBC network wants to construct a 95% confidence interval for p, the proportion of preteen and teenage boys who are bullied at least twice per month in Greenland. Have the requirements for a large-sample z-confidence interval been met? Mark all of the following requirements that have been met with yes, and the requirements that have not been met with no. O O The sample is a simple random sample. The parameter of interest is categorical with two possible outcomes, which are considered success and failure. When the sample…arrow_forwardSociologists published a study on the link between the level of masculinity and criminal behavior in men. Using a sample of newly incarcerated men, the researcher identified 1,175 violent events and 540 events in which violence was avoided that the men were involved in. Each of the sampled men took the Masculinity-Femininity Scale (MFS) test to determine his level of masculinity, based on common male stereotyped traits. MFS scores ranged from 0 to 56 points, with lower scores indicating a more masculine orientation. One goal of the research was to compare the mean MFS scores for two groups of men: those involved in violent events and those who avoided violent events. ---. a. Identify the target parameter for this study. Let µ, = mean MFS score for the violent-event group and µ, = mean MFS score for the avoided-violent-event group. Choose the correct answer below. O A. The target parameter of interest is , - Ha. O B. The target parameter of interest is p, - p, (0)2 O c. The target…arrow_forward
- Glencoe Algebra 1, Student Edition, 9780079039897...AlgebraISBN:9780079039897Author:CarterPublisher:McGraw HillHolt Mcdougal Larson Pre-algebra: Student Edition...AlgebraISBN:9780547587776Author:HOLT MCDOUGALPublisher:HOLT MCDOUGALCollege Algebra (MindTap Course List)AlgebraISBN:9781305652231Author:R. David Gustafson, Jeff HughesPublisher:Cengage Learning
- Big Ideas Math A Bridge To Success Algebra 1: Stu...AlgebraISBN:9781680331141Author:HOUGHTON MIFFLIN HARCOURTPublisher:Houghton Mifflin Harcourt