Introduction to Statistics and Data Analysis
5th Edition
ISBN: 9781305750999
Author: Peck Olson Devore
Publisher: CENGAGE C
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Chapter 11.4, Problem 59E
An experiment to determine if an online intervention can reduce references to sex and substance abuse on social networking web sites of adolescents is described in the paper “Reducing At-Risk Adolescents’ Display of Risk Behavior on a Social Networking Web Site” (Archives of Pediatrics and Adolescent Medicine [2009]: 35–41). Researchers selected public MySpace profiles of people who described themselves as between 18 and 20 years old and who referenced sex or substance use (alcohol or drugs) in their profiles. The selected subjects were assigned at random to an intervention group or a control group.
Those in the intervention group were sent an e-mail from a physician about the risks associated with having a public profile and of referencing sex or substance use in their profile. Three months later, networking sites were revisited to see if any changes had been made. The following excerpt is from the paper:
At baseline, 54.2% of subjects referenced sex and 85.3% referenced substance use on their social networking site profiles. The proportion of profiles in which references decreased to O was 13.7% in the intervention group vs. 5.3o/o in the control group for sex (P =.05) and 26% vs. 22% for substance use (P =.61). The proportion of profiles set to “private” at follow-up was 10.5% in the intervention group and 7.4% in the control group (P = .45). The proportion of profiles in which any of these three protective changes were made was 42.1 % in the intervention group and 29.5% in the control group (P = .07).
- a. The quote from the paper references four hypothesis tests. For each test, indicate what hypotheses you think were tested and whether or not the null hypothesis was rejected.
- b. Based on the information provided by the hypothesis tests, what conclusions can be drawn about the effectiveness of the e-mail intervention?
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Chapter 11 Solutions
Introduction to Statistics and Data Analysis
Ch. 11.1 - Consider two populations for which 1 = 30, 1 = 2,...Ch. 11.1 - An individual can take either a scenic route to...Ch. 11.1 - Prob. 3ECh. 11.1 - Prob. 4ECh. 11.1 - The article Plugged In, but Tuned Out (USA TODAY,...Ch. 11.1 - Prob. 6ECh. 11.1 - Prob. 7ECh. 11.1 - The paper If Its Hard to Read, Its Hard to Do...Ch. 11.1 - Is injecting medical cement effective in reducing...Ch. 11.1 - Prob. 10E
Ch. 11.1 - Prob. 11ECh. 11.1 - The paper Mood Food: Chocolate and Depressive...Ch. 11.1 - Prob. 13ECh. 11.1 - Example 11.1 looked at a study comparing students...Ch. 11.1 - Prob. 15ECh. 11.1 - Prob. 16ECh. 11.1 - A newspaper story headline reads Gender Plays Part...Ch. 11.1 - Prob. 18ECh. 11.1 - Fumonisins are environmental toxins produced by a...Ch. 11.1 - A researcher at the Medical College of Virginia...Ch. 11.1 - Do certain behaviors result in a severe drain on...Ch. 11.2 - Suppose that you were interested in investigating...Ch. 11.2 - Head movement evaluations are important because...Ch. 11.2 - To determine if chocolate milk was as effective as...Ch. 11.2 - The humorous paper Will Humans Swim Faster or...Ch. 11.2 - The study described in the paper Marketing Actions...Ch. 11.2 - Prob. 27ECh. 11.2 - The paper Less Air Pollution Leads to Rapid...Ch. 11.2 - The paper The Truth About Lying in Online Dating...Ch. 11.2 - Prob. 30ECh. 11.2 - Prob. 31ECh. 11.2 - The paper Quantitative Assessment of Glenohumeral...Ch. 11.2 - Two proposed computer mouse designs were compared...Ch. 11.2 - Prob. 34ECh. 11.2 - Prob. 35ECh. 11.2 - The authors of the paper Ultrasound Techniques...Ch. 11.3 - Some people seem to believe that you can fix...Ch. 11.3 - Prob. 38ECh. 11.3 - After the 2010 earthquake in Haiti, many...Ch. 11.3 - Prob. 40ECh. 11.3 - The report Audience Insights: Communicating to...Ch. 11.3 - Prob. 42ECh. 11.3 - Prob. 43ECh. 11.3 - Prob. 44ECh. 11.3 - The article Fish Oil Staves Off Schizophrenia (USA...Ch. 11.3 - The report Young People Living on the Edge...Ch. 11.3 - Prob. 47ECh. 11.3 - Prob. 48ECh. 11.3 - Prob. 49ECh. 11.3 - Prob. 50ECh. 11.3 - Prob. 51ECh. 11.3 - The article Spray Flu Vaccine May Work Better Than...Ch. 11.3 - Prob. 53ECh. 11.3 - The following quote is from the article Canadians...Ch. 11.3 - Prob. 55ECh. 11.3 - Women diagnosed with breast cancer whose tumors...Ch. 11.3 - Prob. 57ECh. 11.4 - The paper The Psychological Consequences of Money...Ch. 11.4 - An experiment to determine if an online...Ch. 11.4 - The paper Ready or Not? Criteria for Marriage...Ch. 11 - Prob. 61CRCh. 11 - Prob. 62CRCh. 11 - A deficiency of the trace element selenium in the...Ch. 11 - Prob. 64CRCh. 11 - Prob. 65CRCh. 11 - In a study of a proposed treatment for diabetes...Ch. 11 - When a surgeon repairs injuries, sutures (stitched...Ch. 11 - Prob. 68CRCh. 11 - In a study of memory recall, eight students from a...Ch. 11 - As part of a study to determine the effects of...Ch. 11 - Prob. 71CRCh. 11 - Prob. 72CRCh. 11 - The article Truth and DARE: Tracking Drug...Ch. 11 - The article Softball Sliding Injuries (American...Ch. 11 - Prob. 75CRCh. 11 - Wayne Gretzky was one of ice hockeys most prolific...Ch. 11 - Heres one to sink your teeth into: The authors of...Ch. 11 - Prob. 78CRCh. 11 - Dentists make many people nervous. To see whether...Ch. 11 - Prob. 80CRCh. 11 - Prob. 81CRCh. 11 - Both surface soil and subsoil specimens were taken...
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