Question

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	37	61	74	68	240
	50 or older	33	58	75	94	260

1. Conduct a test of independence to determine whether the hours of sleep on weeknights are independent of age. Use  = .05. Use Table 12.4.
   
   Compute the value of the  ² test statistic (to 2 decimals).
   
   
   The p value is Selectless than .005between .005 and .01between .01 and .025between .025 and .05between .05 and .10greater than .10Item 2
   
   What is your conclusion?
   SelectConclude age and hours of sleep are not independentCannot reject the assumption that age and hours of sleep are independentItem 3
   
2. Using the total sample of 500, estimate the percentage of people who sleep less than 6, 6 to 6.9, 7 to 7.9, and 8 or more hours on weeknights (to 1 decimal).
   

   Less than 6 hours	%
   6 to 6.9 hours	%
   7 to 7.9 hours	%
   8 or more hours	%

Answer 1

Compute the value of the  ² test statistic (to 2 decimals).

x^2=3.69
The p value is Selectless than .005between .005 and .01between .01 and .025between .025 and .05between .05 and .10greater than .10Item 2

P value=0.2970

p value greater than >0.10

What is your conclusion?
SelectConclude age and hours of sleep are not independentCannot reject the assumption that age and hours of sleep are independentItem 3

Ans Cannot reject the assumption that age and hours of sleep are independent

Less than 6 hours	14%
6 to 6.9 hours	23.8%
7 to 7.9 hours	29.8%
8 or more hours	32.4%