The data on hours of sleep discussed in Example 5 also included whether each student was male or female. Here are the separate five-number summaries for “hours of sleep” for the two sexes:
a. Two males reported sleeping 16 hours and one reported sleeping 12 hours. Using this information and the five-number summaries, draw boxplots that allow you to compare the sexes on number of hours slept the previous night. Use a format similar to Figure 7.10.
b. Based on the boxplots in part a, describe the similarities and differences between the sexes for number of hours slept the previous night.
EXAMPLE 5
Stress in Kids The studies reported in News Stories 13 and 15 both included “stress” as one of the important measurements used. But they differed in how they measured stress. In Original Source 13, “2003 CASA National Survey of American Attitudes on Substance Abuse VIII: Teens and Parents,” teenage respondents were asked: How much stress is there in your life? Think of a scale between 0 and 10, where 0 means you usually have no stress at all and 10 means you usually have a very great deal of stress, which number would you pick to indicate how much stress there is in your life? (p. 40) Categorizing responses as low stress (0 to 3), moderate stress (4 to 6), and high stress (7 to 10), the researchers found that low, medium, and high stress were reported by 29%, 45%, and 26% of teens, respectively. For News Story 15, the children were asked more specific questions to measure stress. According to Additional News Story 15, “To gauge their stress, the children were given a standard questionnaire that included questions like: ‘How often have you felt that you couldn’t control the important things in your life?’ “ There is no way to know which method is more likely to produce an accurate measure of “stress,” partly because there is no fixed definition of stress. Stress in one scenario might mean that someone is working hard to finish an exciting project with a tight deadline. In another scenario it might mean that someone feels helpless and out of control. Those two versions are likely to have very different consequences on someone’s health and well-being. What is important is that as a reader, you are informed about how the researchers measured stress in any given study