Matched Pairs
Name_________________________
1. Are America’s top chief executive officers (CEO’s) really worth all that money. To decide, we look at the
annual company percentage increase in revenue versus the CEO’s annual percentage salary increase in that
same company. Does the data indicate that the population mean percentage increase in corporate revenue is
different form the population increase in CEO’s salary?
% for Company
% for CEO
24
21
23
25
25
20
18
14
6
-4
4
19
21
15
37
30
2. The following information is taken from the U. S. Department of Commerce Environmental Data Service. In
the table, the months Jan. to Dec. are listed along with the average temperature in degrees Fahrenheit for
Miami and Honolulu. Do these data indicate that the average temperature in Miami is different from
Honolulu? Use 0.01.
Miami
Honolulu
Jan.
67.5
74.4
Feb.
68
72.6
Mar
71.3
73.3
Apr
74.9
74.7
May
78
76.2
June
80.9
78
July
82.2
79.1
Aug
82.7
79.8
Sept
81.6
79.5
Oct.
77.8
78.4
Nov.
72.3
76.1
Dec.
68.5
73.7
3. A study of fox rabies in 16 southern Germany locations found the mean number of cases of rabies was 4.75
with standard deviation of 2.82. A second random sample of 15 locations in the north had a mean of 3.93
cases of rabies with standard deviation of 2.43. Does this information indicate that there is a difference
in the mean number of cases of fox rabies between the two regions?
4. A patient who had undergone a triple coronary artery bypass was tested in the following way. The patient
took his pulse at rest and then on a treadmill. This was repeated on six different days. The pulse rate 6
minutes after the test and the pulse rate before the test are shown below. Do these data indicate that the
population mean heart rate 6 minutes after the test is higher than before the test. Use 0.05.
Test
Before
After
1
69
85
2
72
79
3
75
83
4
73
84
5
70
87
6
74
78
5. The pathogen Phytophthora capsici causes bell peppers to wilt and die. Because bell peppers are an
important commercial crop, this disease has undergone a great deal of agriculture research. It is thought
that too much water aids the spread of the pathogen. Two fields are under study. The first step in the
research prject is to compare the mean soil water content for the two fields. Use a 5% level of
significance to test the claim that field A has on average higher soil water content than field B.
Field A
Field B
10.2
8.1
15.2
13.4
10.7
8.5
13.8
11.3
15.5
8.4
14.1
12.6
10.4
8
11.4
12.7
9.9
7.1
11.5
12.4
10
13.9
11
11.3
6. Times to test rats trained to climb a sequence of short ladders are shown below. Do these data indicate that
rats receiving larger rewards tend to perform the ladder climb in less time? Use 0.05
Rat
Time (1 pellet)
Time (5 pellets)
1
12.5
11.1
2
13.7
12
3
11.4
12.2
4
12.1
10.6
5
11
11.5
6
10.4
10.5
7
14.6
12.9
8
12.3
11