10.36 The relationship between cell phone use and academic performance. College students are the most rapid adopters of cell phone technology. They use the phone to surf the Internet, watch videos, listen to music, email, and play video games. Because a cell phone is almost always nearby, researchers have begun studying the relationship between cell phone use and various attitudes and behaviors. In one study, researchers assessed the relationship between cell phone use (CPU), cumulative GPA, anxiety, and general life satisfaction (GLS) using 496 students.15

  1. (a) Participants were undergraduates from a large midwestern university. They were recruited during class time from courses in Sociology, General Biology, American Politics, Human Nutrition, and World History. The researchers argued these courses attracted students from a diversity of majors. To participate, students had to consent to have their GPA retrieved. What do you think about this recruitment process? Can we feel comfortable assuming this is an SRS from the population of undergraduates? Write a short summary of your opinions.

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    FIGURE 10.18 Four plots of residuals versus x, Exercise 10.35.

  2. (b) The following table summarizes the pairwise correlations among the four variables. For each pair of variables, test the null hypothesis that the correlation is zero. Make sure to state the test statistic, degrees of freedom, and P-value.

    GPAAnxietyGLS
    CPU−0.2030.0960.012
    GPA0.0040.207
    Anxiety−0.221

  3. (c) Write a short paragraph that summarizes your findings.