Statistics: The Art and Science of Learning from Data (4th Edition)
4th Edition
ISBN: 9780321997838
Author: Alan Agresti, Christine A. Franklin, Bernhard Klingenberg
Publisher: PEARSON
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Chapter 10.3, Problem 41PB
Teeth whitening results One scientific “test of whiteness” tested the effect of a self applied tooth-whitening peroxide gel system in a randomized, controlled clinical trial.9 The 58 adults assigned to the gel whitening group applied the gel after normal brushing according to the manufacturer’s instructions. The fluoride toothpaste group was instructed to brush twice a day. The procedure was repeated for both groups twice a day for 14 days. An experienced examiner determined the tooth shades comparing each tooth to the shade tabs from an accepted shade scale (Vita shade guide) at the start of the experiment to create a baseline and then after one and two weeks of product application. Changes between the baseline score and the one-and two-week assessments were expressed as a difference of the respective Vita score, with a positive difference indicating an improvement in tooth whiteness. The results of the study are shown in the following table.
- a. State the hypotheses that were tested for the change from baseline
means . - b. The P-value is reported as <0.05 for the test comparing the means. Explain how to interpret this value.
- c. Calculate the pooled standard error, the t statistic, and the resulting P-value.
- d. The ratio of the change from baseline sample means was 2.91. Interpret this ratio.
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Morgan City Fire Chief Sidney Pyro is concerned about the low efficiency scores that his firefighters receive at the state testing institute. Chief Pyro believes that these scores result because some firefighters are not in good physical condition. Pyro orders 75 randomly selected firefighters to participate in an hour of exercise per day. Another 200 firefighters have no required exercise. After 60 days, all firefighters are tested again by the state. Chief Pyro collects the data and performs a two-sample independent t-test by using SPSS to examine if there is a statistically significant difference between the treatment and control groups; the SPSS results are shown in the table below.
Groups
N
Mean
Std. Deviation
Std. Error Mean
Test Scores
Treatment
75
74.5
31.4
3.6
Control
200
70.6
26.3
1.9
Formulate a null and research hypothesis:
H0:
H1:
Collect all the necessary data:
Mean score of the treatment group:
Mean score of the control group:
Sample size of the…
Morgan City Fire Chief Sidney Pyro is concerned about the low efficiency scores that his firefighters receive at the state testing institute. Chief Pyro believes that these scores result because some firefighters are not in good physical condition. Pyro orders 75 randomly selected firefighters to participate in an hour of exercise per day. Another 200 firefighters have no required exercise. After 60 days, all firefighters are tested again by the state. Chief Pyro collects the data and performs a two-sample independent t-test by using SPSS to examine if there is a statistically significant difference between the treatment and control groups; the SPSS results are shown in the table below.
Group Statistics
Groups
N
Mean
Std. Deviation
Std. Error Mean
Test Scores
Treatment
75
74.5
31.4
3.6
Control
200
70.6
26.3
1.9
a. Formulate a null and research hypothesis:
H0:
H1:
Collect all the necessary data:
Mean score of the treatment group:…
Hospital floors: Hospital floors are usually bare tiles instead of carpet. Carpets will decrease noise but might increase germ growth.
To study this, researchers installed carpet in 8 of 16 hospital rooms. They randomly selected the rooms to carpet. The other rooms had bare tiles. After two weeks of normal use, they collected air samples from the rooms and counted the bacteria in each sample.
Based on this description of the experiment, which of the following is a part of the experiment design? Check all that apply.
Group of answer choices
Chapter 10 Solutions
Statistics: The Art and Science of Learning from Data (4th Edition)
Ch. 10.1 - Unemployment rate According to the Bureau of Labor...Ch. 10.1 - Prob. 2PBCh. 10.1 - Binge drinking The PACE project at the University...Ch. 10.1 - Smoking and lung obstruction A National Center for...Ch. 10.1 - Do you believe in miracles? Let p1 and p2 denote...Ch. 10.1 - Aspirin and heart attacks in Sweden A Swedish...Ch. 10.1 - Swedish study test Refer to the previous exercise....Ch. 10.1 - Significance test for aspirin and cancer deaths...Ch. 10.1 - Prob. 9PBCh. 10.1 - Comparing marketing commercials Two TV commercials...
Ch. 10.1 - Hormone therapy for menopause The Womens Health...Ch. 10.1 - Obama A/B testing To increase Barack Obamas...Ch. 10.1 - Believe in heaven and hell A recent survey asked...Ch. 10.2 - Alcohol and Energy Drinks A 2013 article in the...Ch. 10.2 - Address global warming You would like to determine...Ch. 10.2 - Housework for women and men Do women tend to spend...Ch. 10.2 - More confident about housework Refer to part c in...Ch. 10.2 - Employment by gender The study described in...Ch. 10.2 - Ideal number of children In 2014, the GSS asked,...Ch. 10.2 - Pay by gender The study described in the Exercise...Ch. 10.2 - Bulimia CI A study of bulimia among college women...Ch. 10.2 - Chelation useless? Chelation is an alternative...Ch. 10.2 - Nicotine dependence A study on nicotine dependence...Ch. 10.2 - Inhaling affect HONC? Refer to the previous...Ch. 10.2 - Females or males more nicotine dependent? Refer to...Ch. 10.2 - Female and male monthly smokers Refer to the...Ch. 10.2 - Body language In an experiment investigating body...Ch. 10.2 - Student survey Refer to the FL Student Survey data...Ch. 10.2 - Study time A graduate teaching assistant for...Ch. 10.2 - More on study time Refer to the data in the...Ch. 10.2 - Time spent on social networks As part of a class...Ch. 10.2 - More time on social networks In the previous...Ch. 10.2 - Normal assumption The methods of this section make...Ch. 10.2 - Vital capacity One of the authors of this book has...Ch. 10.3 - Body dissatisfaction Female college student...Ch. 10.3 - Body dissatisfaction test Refer to the previous...Ch. 10.3 - Surgery versus placebo for knee pain Refer to...Ch. 10.3 - Comparing clinical therapies A clinical...Ch. 10.3 - Clinical therapies 2 Refer to the previous...Ch. 10.3 - Vegetarians more liberal? When a sample of social...Ch. 10.3 - Teeth whitening results One scientific test of...Ch. 10.3 - Permuting therapies Refer to Exercise 10.38, which...Ch. 10.3 - Permutations equally likely Refer to the previous...Ch. 10.3 - Two-sided permutation P-value Refer to the...Ch. 10.3 - Time spent on social networks revisited Exercise...Ch. 10.3 - Compare permutation test to t test Refer to the...Ch. 10.3 - Dominance of politicians For a rating experiment,...Ch. 10.3 - Sampling distribution of x1x2 Refer to Example 12,...Ch. 10.4 - Does exercise help blood pressure? Several recent...Ch. 10.4 - Test for blood pressure Refer to the previous...Ch. 10.4 - Social activities for students As part of her...Ch. 10.4 - More social activities Refer to the previous...Ch. 10.4 - Movies versus parties Refer to the previous two...Ch. 10.4 - Freshman 15 a myth? The freshman 15 is the name of...Ch. 10.4 - Checking for freshman 15 Refer to the previous...Ch. 10.4 - Internet book prices Annas project for her...Ch. 10.4 - Comparing hook prices 2 For the data in the...Ch. 10.4 - Lung capacity revisited Refer to Exercise 10.34...Ch. 10.4 - Comparing speech recognition systems Table 1020 in...Ch. 10.4 - Treat juveniles as adults? The table that follows...Ch. 10.4 - Change coffee brand? A study was conducted to see...Ch. 10.4 - Presidents popularity Last month a random sample...Ch. 10.4 - Heaven and hell Results of polls about belief in...Ch. 10.4 - Heaven and hell around the world Refer to the...Ch. 10.5 - Prob. 65PBCh. 10.5 - Prob. 66PBCh. 10.5 - Basketball paradox The following list summarizes...Ch. 10.5 - Prob. 68PBCh. 10.5 - Prob. 69PBCh. 10.5 - Prob. 70PBCh. 10.5 - Breast cancer over time The percentage of women...Ch. 10 - Pick the method Steve Solomon, the owner of...Ch. 10 - Prob. 73CPCh. 10 - BMI then and now The Centers for Disease Control...Ch. 10 - Marijuana and gender In a survey conducted by...Ch. 10 - Prob. 76CPCh. 10 - Belief depend on gender? Refer to the previous...Ch. 10 - Prob. 78CPCh. 10 - Prob. 79CPCh. 10 - Prob. 80CPCh. 10 - Prob. 81CPCh. 10 - Prob. 82CPCh. 10 - Prob. 83CPCh. 10 - Prob. 84CPCh. 10 - Prob. 85CPCh. 10 - How often do you feel sad? A recent General Social...Ch. 10 - Prob. 87CPCh. 10 - Prob. 88CPCh. 10 - Prob. 89CPCh. 10 - Equal pay in sports? The following data refer to a...Ch. 10 - Prob. 91CPCh. 10 - Prob. 92CPCh. 10 - Anorexia again Refer to Exercise 10.89, comparing...Ch. 10 - Breast-feeding helps IQ? A Danish study of...Ch. 10 - Prob. 95CPCh. 10 - Prob. 96CPCh. 10 - Prob. 97CPCh. 10 - Prob. 98CPCh. 10 - Prob. 99CPCh. 10 - Prob. 100CPCh. 10 - Prob. 101CPCh. 10 - Prob. 102CPCh. 10 - Prob. 103CPCh. 10 - Prob. 104CPCh. 10 - Belief in ghosts and in astrology A poll by Louis...Ch. 10 - Death penalty paradox Exercise 3.58 showed results...Ch. 10 - Prob. 107CPCh. 10 - Prob. 108CPCh. 10 - Prob. 109CPCh. 10 - Prob. 111CPCh. 10 - Pay discrimination against women? A Time Magazine...Ch. 10 - Mean of permutation distribution Refer to Example...Ch. 10 - Treating math anxiety Two new programs were...Ch. 10 - Prob. 115CPCh. 10 - Prob. 116CPCh. 10 - Prob. 117CPCh. 10 - Multiple choice: Sample size and significance If...Ch. 10 - Prob. 119CPCh. 10 - Prob. 120CPCh. 10 - Prob. 121CPCh. 10 - Prob. 122CPCh. 10 - Prob. 123CPCh. 10 - Prob. 124CPCh. 10 - Prob. 125CPCh. 10 - Prob. 126CPCh. 10 - Null standard error for matched pairs Under the...Ch. 10 - Prob. 128CP
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