The Essentials of Statistics: A Tool for Social Research
4th Edition
ISBN: 9781305802698
Author: Joseph F. Healey
Publisher: Cengage Learning US
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Textbook Question
Chapter 2, Problem 2.10P
PA/CJ As part of an evaluation of the efficiency of your local police force, you have gathered the following data on police response tie to calls for assistance during two different years. (Response times were rounded off to whole minutes.) Convert both frequency distributions into percentages, and write a paragraph comparing the changes in response time between the two years.
| Response Time, 2000 | Frequency (f) |
| 21 minutes or more | 20 |
| 16-20 minutes | 90 |
| 11-15 minutes | 185 |
| 6-10 minutes | 370 |
| Less than 6 minutes | 210 |
| Total | 875 |
| Response Time, 2010 | Frequency (f) |
| 21 minutes or more | 45 |
| 16-20 minutes | 95 |
| 11-15 minutes | 155 |
| 6-10 minutes | 350 |
| Less than 6 minutes | 250 |
| Total | 895 |
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Question 4
An article in Quality Progress (May 2011, pp. 42-48) describes the use of factorial experiments to improve a
silver powder production process. This product is used in conductive pastes to manufacture a wide variety of
products ranging from silicon wafers to elastic membrane switches. Powder density (g/cm²) and surface area
(cm/g) are the two critical characteristics of this product. The experiments involved three factors: reaction
temperature, ammonium percentage, stirring rate. Each of these factors had two levels, and the design was
replicated twice. The design is shown in Table 3.
A222222222222233
Stir Rate
(RPM)
Ammonium
(%)
Table 3: Silver Powder Experiment from Exercise 13.23
Temperature
(°C)
Density
Surface Area
100
8
14.68
0.40
100
8
15.18
0.43
30
100
8
15.12
0.42
30
100
17.48
0.41
150
7.54
0.69
150
8
6.66
0.67
30
150
8
12.46
0.52
30
150
8
12.62
0.36
100
40
10.95
0.58
100
40
17.68
0.43
30
100
40
12.65
0.57
30
100
40
15.96
0.54
150
40
8.03
0.68
150
40
8.84
0.75
30
150…
Chapter 2 Solutions
The Essentials of Statistics: A Tool for Social Research
Ch. 2 - SOC The table that follows reports the marital...Ch. 2 - SOC At. St. Winnefred Hospital, the number of...Ch. 2 - CJ The town of Shinbone, Kansas, has a population...Ch. 2 - CJ The numbers of homicides in five U.S. states...Ch. 2 - SOC The scores of 15 respondents on four variables...Ch. 2 - SW A local youth service agency has begun a sex...Ch. 2 - Twenty-five residents of a community for senior...Ch. 2 - GER Twenty-five residents of a community for...Ch. 2 - SOC Twenty-five students completed a questionnaire...Ch. 2 - PA/CJ As part of an evaluation of the efficiency...
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