In: Statistics and Probability
The National Sleep Foundation used a survey to determine whether
hours of sleeping per night are independent of age
(Newsweek, January 19, 2004). The following show the hours
of sleep on weeknights for a sample of individuals age 49 and
younger and for a sample of individuals age 50 and older.
Hours of Sleep | |||||||
Age | Fewer than 6 | 6 to 6.9 | 7 to 7.9 | 8 or more | Total | ||
49 or younger | 34 | 58 | 80 | 68 | 240 | ||
50 or older | 35 | 64 | 70 | 91 | 260 |
Less than 6 hours | % |
6 to 6.9 hours | % |
7 to 7.9 hours | % |
8 or more hours | % |