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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Chapter 8, Problem 8.14P
| Sample 1 (Crime line Crimes Cleared by Arrest) |
Sample 2 (Non-Crime line Crimes Cleared by Arrest) |
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What were the average sales for the four weeks prior to the experiment?
What were the sales during the four weeks when the stores used the digital display?
What is the mean difference in sales between the experimental and regular POP time periods?
State the null hypothesis being tested by the paired sample t-test.
Do you reject or retain the null hypothesis?
At a 95% significance level, was the difference significant? Explain why or why not using the results from the paired sample t-test.
Should the manager of the retail chain install new digital displays in each store? Justify your answer.
A retail chain is interested in determining whether a digital video point-of-purchase (POP) display would stimulate higher sales for a brand advertised compared to the standard cardboard point-of-purchase display. To test this, a one-shot static group design experiment was conducted over a four-week period in 100 different stores. Fifty stores were randomly assigned to the control treatment (standard display) and the other 50 stores were randomly assigned to the experimental treatment (digital display). Compare the sales of the control group (standard POP) to the experimental group (digital POP).
What were the average sales for the standard POP display (control group)?
What were the sales for the digital display (experimental group)?
What is the (mean) difference in sales between the experimental group and control group?
List the null hypothesis being tested.
Do you reject or retain the null hypothesis based on the results of the independent t-test?
Was the difference between the…
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 8 Solutions
The Essentials of Statistics: A Tool for Social Research
Ch. 8 - For each of the following, test for the...Ch. 8 - Two sociologists administered questionnaires to...Ch. 8 - Do athletes in different sports vary in terms of...Ch. 8 - PA A number of years ago, the road and highway...Ch. 8 - SOC Are middle-class families more likely than...Ch. 8 - SOC Are college students who live in dormitories...Ch. 8 - GER Are senior citizens who live in retirement...Ch. 8 - As the director of the local Boys Club, you have...Ch. 8 - SOC A survey has been administered to random...Ch. 8 - For each problem, test the sample proportions for...
Ch. 8 - CJ About half of the police officers in Shinbone,...Ch. 8 - SW A large counseling center needs to evaluate...Ch. 8 - SOC At St. Algebra College, the sociology and...Ch. 8 - CJ The mayor of a large city started a crimeline...Ch. 8 - Prob. 8.15PCh. 8 - A researcher is studying the effects of the...
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