The National Sleep Foundation used a survey to determine whetherhours of sleeping per night are independent of age(Newsweek, January 19, 2004). The following show the hoursof sleep on weeknights for a sample of individuals age 49 andyounger and for a sample of individuals age 50 and older.
| Hours ofSleep |
| Age | Fewer than 6 | 6 to 6.9 | 7 to 7.9 | 8 or more | Total | |
| 49 or younger | 30 | 64 | 76 | 70 | 240 | |
| 50 or older | 30 | 58 | 80 | 92 | 260 | |
Conduct a test of independence to determine whether the hours ofsleep on weeknights are independent of age. Use  = .05.Use Table 12.4.
Compute the value of the X2 (Chi2) test statistic (to 2decimals).????
b) Using the total sample of 500, estimate the percentage ofpeople who sleep less than 6, 6 to 6.9, 7 to 7.9, and 8 or morehours on weeknights (to 1 decimal).
| Less than 6 hours | Â Â % |
| 6 to 6.9 hours | Â Â % |
| 7 to 7.9 hours | Â Â % |
| 8 or more hours | Â Â % |
