Chapter 11, Problem 11.7AC

The researchers hypothesised that people who receive an audiovisual presentation will have a different mean level of recall of ad information as those who receive only the visual aspects of the ad. What significance test should the researchers use for testing their hypothesis?

A​ case-control (or​ retrospective) study was conducted to investigate a relationship between the colors of helmets worn by motorcycle drivers and whether they are injured or killed in a crash. Results are given in the accompanying table. Using a 0.05 significance​ level, test the claim that injuries are independent of helmet color.       Color of Helmet         Black White Yellow Red Blue     Controls​ (not injured)   479 346 32 164 88     Cases​ (injured or​ killed)   201 99 9 67 43

• Facilitators of career guidance claim that 60% of the participants prefer to take Psychology in college. In a career guidance seminar, 30 participants were asked what they intend to take in college and it was found out that only 16 of them would like to enrol Psychology in college. Is the data an evidence to support the facilitators' claim at 10% level of significance? The mean number of sick days an employee takes per year is believed to be about ten. Members of a personnel department do not believe this figure. They randomly survey eight employees. The number of sick days they took for the past year are as follows: 7; 4; 15; 3; 11; 12; 6; 8. Should the personnel team believe that the mean number is ten at a = 0.05? (Use p-value to to discuss the results)

Researchers interested in the effects of caffeine on anxiety have randomly assigned participants to one of two conditions in a study, the no caffeine condition or the caffeine condition. After drinking two cups of either regular or decaffeinated coffee, participants will take an anxiety inventory a. What is the independent variable in this study? b. What is the dependent variable in this study? c. Identify the control and experimental groups in this study. d. Is the independent variable manipulated or a participant variable?

A social psychological study sampling male and female 8th graders across 34 countries indicated that there is a negative correlation between each country's level of gender stereotypes and girls' academic achievement scores on math and sciences (relative to boys' scores). Which of the following interpretations is NOT valid? O a. Gender stereotypes might have affected girls' relative academic performance on math and sciences such that in a country where gender stereotypes are stronger, girls perform more poorly on math and sciences compared with boys. O b. Girls' relative academic performances on math and sciences can be attributable to gender stereotypes of the country. That is, gender stereotypes cause and determine girls' relative academic performances on math and sciences c. There may be unknown third variables such as parents' expectation or socioeconomic status that might have affected both gender stereotypes and girls' relative academic performance on math and sciences in those…

A case-control (or retrospective) study was conducted to investigate a relationship between the colors of helmets worn by motorcycle drivers and whether they are injured or killed in a crash. Results are given in the accompanying table. Using a 0.01 significance level, test the claim that injuries are independent of helmet color. Color of Helmet Black White Yellow Red Blue Controls (not injured) Cases (injured or killed) 483 200 354 32 167 90 111 9. 70 44 Click here to view the chi-square distribution table. Identify the null and alternative hypotheses. Choose the correct answer below. O A. Ho: Injuries and helmet color are dependent H,: Injuries and helmet color are independent O B. Ho: Whether a crash occurs and helmet color are dependent H: Whether a crash occurs and helmet color are independent O C. Ho: Injuries and helmet color are independent H,: Injuries and helmet color are dependent O D. Ho: Whether a crash occurs and helmet color are independent H,: Whether a crash occurs and…

A study by Bettmann (2007) published in the Journal of the American Psychoanalytic Association assessed whether the attachment relationships between adolescents and their parents changed as a result of a residential wilderness treatment experience for the adolescents. Participants completed the Adolescent Attachment Questionnaire at the start and at the end of the wilderness program. Which statistical test should be used to determine whether the wilderness treatment affected attachment relationships? a. dependent-samples t test b. z test c. independent samples t-test d. one-sample t test

2 Researchers examined the relationship between interpersonal violence and health in college-age women. The researchers administered a psychological distress questionnaire which produced a score on a scale of 0-12. What would be an appropriate measure of central tendency to consider for this variable?

A clinical psychologist is investigating the relationship between sleep and feelings ofanxiety. For a sample of 15 individuals, he asks each participant to indicate how many hours theytypically sleep each night and each participant also completes an anxiety assessment. The followingdata is obtained:Hours of sleep: M=6.0 SS=16.0Anxiety scores: M=8.0 SS=64.0SP = - 20.0   b. Describe the nature of the relationship between these two variables