For Exercise 2.91, see page 106; for 2.92 and 2.93, see pages 106–107; for 2.94 to 2.96, see page 108; for 2.97 to 2.99, see page 109; and for 2.100 and 2.101, see pages 111–112.

Question 2.104

2.104 Exercise and adequate sleep

A survey of 656 boys and girls, ages 13 to 18, asked about adequate sleep and other health-related behaviors. The recommended amount of sleep is six to eight hours per night.19 In the survey, 54% of the respondents reported that they got less than this amount of sleep on school nights. The researchers also developed an exercise scale that was used to classify the students as above or below the median in how much they exercised. Here is the table of counts with students classified as getting or not getting adequate sleep and by the exercise variable:

sleep

114

Exercise
Enough sleep High Low
Yes 151 115
No 148 242
  1. Find the distribution of adequate sleep for the high exercisers.
  2. Do the same for the low exercisers.
  3. If you have the appropriate software, use a mosaic plot to illustrate the marginal distribution of exercise and your results in parts (a) and (b).
  4. Summarize the relationship between adequate sleep and exercise using the results of parts (a) and (b).