A survey was conducted to determine whether hours of sleep per night are independent of age. A sample of individuals was asked to indicate the number of hours of sleep per night with categorical options: fewer than 6 hours, 6 to 6.9 hours. 7 to 7.9 hours, and 8 hours or more. Later in the survey, the individuals were asked to indicate their age with categorical options: age 39 or younger and age 40 or older. Sample data follow. Age Group Hours of Sleep 39 or younger 40 or older Fewer than 6 37 35 6 to 6.9 60 57 7 to 7.9 78 76 8 or more 65 92 (a) Conduct a test of independence to determine whether hours of sleep are independent of age. (b) What is your estimate of the percentages of individuals who sleep fewer than 6 hours, 6 to 6.9 hours, 7 to 7.9 hours, and 8 hours or more per night?

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Chapter10: Statistics
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Problem 13PT
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A survey was conducted to determine whether hours of sleep per night are independent of age. A sample of
individuals was asked to indicate the number of hours of sleep per night with categorical options: fewer than 6
hours, 6 to 6.9 hours, 7 to 7.9 hours, and 8 hours or more. Later in the survey, the individuals were asked to
indicate their age with categorical options: age 39 or younger and age 40 or older. Sample data follow.
Age Group
Hours of Sleep
39 or younger
40 or older
Fewer than 6
37
35
6 to 6.9
60
57
7 to 7.9
78
76
8 or more
65
92
(a) Conduct a test of independence to determine whether hours of sleep are independent of age.
(b) what is your estimate of the percentages of individuals who sleep fewer than 6 hours, 6 to 6.9 hours, 7
to 7.9 hours, and 8 hours or more per night?
Transcribed Image Text:A survey was conducted to determine whether hours of sleep per night are independent of age. A sample of individuals was asked to indicate the number of hours of sleep per night with categorical options: fewer than 6 hours, 6 to 6.9 hours, 7 to 7.9 hours, and 8 hours or more. Later in the survey, the individuals were asked to indicate their age with categorical options: age 39 or younger and age 40 or older. Sample data follow. Age Group Hours of Sleep 39 or younger 40 or older Fewer than 6 37 35 6 to 6.9 60 57 7 to 7.9 78 76 8 or more 65 92 (a) Conduct a test of independence to determine whether hours of sleep are independent of age. (b) what is your estimate of the percentages of individuals who sleep fewer than 6 hours, 6 to 6.9 hours, 7 to 7.9 hours, and 8 hours or more per night?
Now that we have the observed and expected frequencies, the other components for the test statistic can be
found. The following table gives the given observed data and the calculated expected frequencies. The sum of
all the values in the final column will be the x test statistic.
Complete the table, rounding values in the final column to four decimal places and x" to three decimal places.
Squared
Difference
Divided by
Expected
Frequency
Squared
Difference
Observed
Expected
Frequency
Hours
Difference
Age
Group
Frequency
of
-e,
Sleep
z("a - ")
5.9536
39 or
2.442 =
5.9536
Fewer
37 - 34.56 =
37
34.56
34.56
than 6
younger
2.44
0.1723
Fewer
than 6
40 or
0.159
35
37.44
-2.44
5.9536
older
6 to
39 or
3.84
60
56.16
14.7456
0.2626
6.9
younger
6 to
6.9
40 or
57
60.84
-3.84
0.2424
older
7 to
39 or
78
73.92
4.08
16.6464
7.9
younger
7 to
40 or
older
76
80.08
-4.08
16.6464
7.9
8 or
39 or
|-10.38
65
75.36
107.3296
1.4242
mоre
younger
40 or
older
8 or
92
81.64
10.36
107.3296
more
(f, - e,
4.008
Transcribed Image Text:Now that we have the observed and expected frequencies, the other components for the test statistic can be found. The following table gives the given observed data and the calculated expected frequencies. The sum of all the values in the final column will be the x test statistic. Complete the table, rounding values in the final column to four decimal places and x" to three decimal places. Squared Difference Divided by Expected Frequency Squared Difference Observed Expected Frequency Hours Difference Age Group Frequency of -e, Sleep z("a - ") 5.9536 39 or 2.442 = 5.9536 Fewer 37 - 34.56 = 37 34.56 34.56 than 6 younger 2.44 0.1723 Fewer than 6 40 or 0.159 35 37.44 -2.44 5.9536 older 6 to 39 or 3.84 60 56.16 14.7456 0.2626 6.9 younger 6 to 6.9 40 or 57 60.84 -3.84 0.2424 older 7 to 39 or 78 73.92 4.08 16.6464 7.9 younger 7 to 40 or older 76 80.08 -4.08 16.6464 7.9 8 or 39 or |-10.38 65 75.36 107.3296 1.4242 mоre younger 40 or older 8 or 92 81.64 10.36 107.3296 more (f, - e, 4.008
Expert Solution
Step 1 Part a

The computation is done as follow:

Hours of sleep Age group Observed frequencies (Oij) Expected frequencies (Eij) Eij-Oij Eij-Oij2 Eij-Oij2Eij
Fewer than 6 39 or younger 37 34.56 2.44 5.9536 0.172269
6 to 6.9 39 or younger 60 56.16 3.84 14.7456 0.262564
7 to 7.9 39 or younger 78 73.92 4.08 16.6464 0.225195
8 or more 39 or younger 65 75.36 -10.36 107.3296 1.424225
Fewer than 6 40 or older 35 37.44 -2.44 5.9536 0.159017
6 to 6.9 40 or older 57 60.84 -3.84 14.7456 0.242367
7 to 7.9 40 or older 76 80.08 -4.08 16.6464 0.207872
8 or more 40 or older 92 81.64 10.36 107.3296 1.314669

 

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