The national sleep foundation used a survey to determine whether hours of sleeping per night are independent of age. 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.
|
age
|
fewer than 6
|
6 to 6.9
|
7 to 7.9
|
8 or more
|
total
|
|
49 or younger
|
38
|
60
|
77
|
65
|
240
|
|
50 or older
|
36
|
57
|
75
|
92
|
260
|
a. Conduct a test of independence to determine whether the hours of sleep on weeknights are independent of age. Use α =.05 what is the p-value and what is your conclusion.
b. What IS your estimate of the percentage of people who sleep fewer than 6hours, 6 to 6.9 hours, 7 to 7.9 hours and 8 or more hours on weeknights?