ELEMENTARY STATISTICS(LL)(FD)
3rd Edition
ISBN: 9781260707458
Author: Navidi
Publisher: MCGRAW-HILL CUSTOM PUBLISHING
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Textbook Question
Chapter 1.3, Problem 30E
Another Salk Vaccine Trial: Another study of the Salk vaccine, conducted at the same time as the trial described in Exercise 29, used a different design. In this study, approximately 350,000 second graders were invited to participate. About 225,000 did so, and the other 125,000 refused. All of the participating second graders received the vaccine. The control group consisted of approximately 725,000 first and third graders.
They were not given any placebo, so no consent was necessary.
- Was this a randomized experiment?
- Was it double-blind?
- The treatment group consisted of children who had consent to participate. The control group consisted of all first and third graders. It turned out that the results of this study seriously underestimated the effectiveness of the vaccine. Use the information provided in Exercise 29(c) to explain why.
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state whether the investigation in question is an observational study or a designed experiment. Justify your answer in each case.
The Salk Vaccine. In the 1940s and early 1950s, the public was greatly concerned about polio. In an attempt to prevent this disease, Jonas Salk of the University of Pittsburgh developed a polio vaccine. In a test of the vaccine’s efficacy, involving nearly 2 million grade-school children, half of the children received the Salk vaccine; the other half received a placebo, in this case an injection of salt dissolved in water. Neither the children nor the doctors performing the diagnoses knew which children belonged to which group, but an evaluation center did. The center found that the incidence of polio was far less among the children inoculated with the Salk vaccine. From that information, the researchers concluded that the vaccine would be effective in preventing polio for all U.S. school children; consequently, it was made available for general use.
A psychologist has developed a mental alertness test. She wishes to study the effects (if any) of type of food consumed on mental alertness. Twenty-one volunteers were randomly divided into two groups. Both groups were told to eat the amount they usually eat for lunch at noon. At 2:00 P.M., all subjects were given the alertness test. Group A had a low-fat lunch with no red meat, lots of vegetables, carbohydrates, and fiber. Group B had a high-fat lunch with red meat, vegetable oils, and low fiber. The only drink for both groups was water. The test scores are shown below.
Group A
67
93
82
69
76
47
43
58
92
63
52
Group B
70
57
75
59
66
49
55
46
45
91
89
72
Use a 10% level of significance to test the claim that there is no difference in mental alertness distributions based on type of lunch.
(a) What is the level of significance?
(b) Compute the sample test statistic. (Use 2 decimal places.)
(c) Find the P-value of the sample test statistic. (Use 4 decimal places.)
A psychologist has developed a mental alertness test. She wishes to study the effects (if any) of type of food consumed on mental alertness. Twenty-one volunteers were randomly divided into two groups. Both groups were told to eat the amount they usually eat for lunch at noon. At 2:00 P.M., all subjects were given the alertness test. Group A had a low-fat lunch with no red meat, lots of vegetables, carbohydrates, and fiber. Group B had a high-fat lunch with red meat, vegetable oils, and low fiber. The only drink for both groups was water. The test scores are shown below.
Group A
75
82
96
54
78
59
67
53
97
85
66
Group B
70
80
79
60
62
71
52
69
64
88
51
74
Use a 10% level of significance to test the claim that there is no difference in mental alertness distributions based on type of lunch.
(a) What is the level of significance?State the null and alternate hypotheses.
Ho: Distributions are different. H1: Distributions are the same.Ho: Distributions are the same. H1:…
Chapter 1 Solutions
ELEMENTARY STATISTICS(LL)(FD)
Ch. 1.1 - In Exercises 7—12, fill in each blank with the...Ch. 1.1 - In Exercises 7—12, fill in each blank with the...Ch. 1.1 - In Exercises 7—12, fill in each blank with the...Ch. 1.1 - In Exercises 7—12, fill in each blank with the...Ch. 1.1 - In Exercises 7—12, fill in each blank with the...Ch. 1.1 - In Exercises 7—12, fill in each blank with the...Ch. 1.1 - In Exercises 13—16, determine whether the...Ch. 1.1 - In Exercises 13—16, determine whether the...Ch. 1.1 - In Exercises 13—16, determine whether the...Ch. 1.1 - In Exercises 13—16, determine whether the...
Ch. 1.1 - In Exercises 17—20, determine whether the number...Ch. 1.1 - In Exercises 17—20, determine whether the number...Ch. 1.1 - In Exercises 17—20, determine whether the number...Ch. 1.1 - In Exercises 17—20, determine whether the number...Ch. 1.1 - Exercises 21—24 refer to the population of...Ch. 1.1 - Exercises 21—24 refer to the population of...Ch. 1.1 - Exercises 21—24 refer to the population of...Ch. 1.1 - Exercises 21—24 refer to the population of...Ch. 1.1 - In Exercises 25—36, identify the kind of sample...Ch. 1.1 - In Exercises 25—36, identify the kind of sample...Ch. 1.1 - In Exercises 25—36, identify the kind of sample...Ch. 1.1 - In Exercises 25—36, identify the kind of sample...Ch. 1.1 - In Exercises 25—36, identify the kind of sample...Ch. 1.1 - In Exercises 25—36, identify the kind of sample...Ch. 1.1 - In Exercises 25—36, identify the kind of sample...Ch. 1.1 - In Exercises 25—36, identify the kind of sample...Ch. 1.1 - In Exercises 25—36, identify the kind of sample...Ch. 1.1 - In Exercises 25—36, identify the kind of sample...Ch. 1.1 - In Exercises 25—36, identify the kind of sample...Ch. 1.1 - In Exercises 25—36, identify the kind of sample...Ch. 1.1 - Computer network: Every third day, a computer...Ch. 1.1 - Smartphone apps: A smartphone app produces a...Ch. 1.1 - Youre giving me a headache: A pharmaceutical...Ch. 1.1 - Pay more for recreation? The director of the...Ch. 1.1 - Voter preferences: A pollster wants to sample 500...Ch. 1.1 - Quality control: Products come off an assembly...Ch. 1.1 - On-site day care: A large company wants to sample...Ch. 1.1 - The tax man cometh: The Internal Revenue Service...Ch. 1.1 - Draw a sample: Imagine that you are asked to...Ch. 1.1 - A systematic sample is a cluster sample: Explain...Ch. 1.2 - In Exercises 5—10, fill in each blank with the...Ch. 1.2 - In Exercises 5—10, fill in each blank with the...Ch. 1.2 - In Exercises 5—10, fill in each blank with the...Ch. 1.2 - In Exercises 5—10, fill in each blank with the...Ch. 1.2 - In Exercises 5—10, fill in each blank with the...Ch. 1.2 - In Exercises 5—10, fill in each blank with the...Ch. 1.2 - In Exercises 11—14, determine whether the...Ch. 1.2 - In Exercises 11—14, determine whether the...Ch. 1.2 - In Exercises 11—14, determine whether the...Ch. 1.2 - In Exercises 11—14, determine whether the...Ch. 1.2 - In Exercises 15—24, determine whether the data...Ch. 1.2 - In Exercises 15—24, determine whether the data...Ch. 1.2 - In Exercises 15—24, determine whether the data...Ch. 1.2 - In Exercises 15—24, determine whether the data...Ch. 1.2 - In Exercises 15—24, determine whether the data...Ch. 1.2 - In Exercises 15—24, determine whether the data...Ch. 1.2 - In Exercises 15—24, determine whether the data...Ch. 1.2 - In Exercises 15—24, determine whether the data...Ch. 1.2 - In Exercises 15—24, determine whether the data...Ch. 1.2 - In Exercises 15—24, determine whether the data...Ch. 1.2 - In Exercises 25—32, determine whether the data...Ch. 1.2 - In Exercises 25—32, determine whether the data...Ch. 1.2 - In Exercises 25—32, determine whether the data...Ch. 1.2 - In Exercises 25—32, determine whether the data...Ch. 1.2 - In Exercises 25—32, determine whether the data...Ch. 1.2 - In Exercises 25—32, determine whether the data...Ch. 1.2 - In Exercises 25—32, determine whether the data...Ch. 1.2 - In Exercises 25—32, determine whether the data...Ch. 1.2 - In Exercises 33—40, determine whether the data...Ch. 1.2 - In Exercises 33—40, determine whether the data...Ch. 1.2 - In Exercises 33—40, determine whether the data...Ch. 1.2 - In Exercises 33—40, determine whether the data...Ch. 1.2 - In Exercises 33—40, determine whether the data...Ch. 1.2 - In Exercises 33—40, determine whether the data...Ch. 1.2 - In Exercises 33—40, determine whether the data...Ch. 1.2 - In Exercises 33—40, determine whether the data...Ch. 1.2 - Music Videos: Following are the most-viewed videos...Ch. 1.2 - More Videos: The following table presents the...Ch. 1.2 - Hows the economy? A poll conducted by the American...Ch. 1.2 - Global warming: A recent Pew poll asked people...Ch. 1.2 - Graphic Novels: According to Time magazine, some...Ch. 1.2 - Watch sour language: According to Merriam Webster...Ch. 1.2 - Top ten video games: According to Wikipedia, the...Ch. 1.2 - At the movies: The following table provides...Ch. 1.2 - What do the numbers mean? A survey is administered...Ch. 1.3 - In Exercises 5—10, fill in each blank with the...Ch. 1.3 - In Exercises 5—10, fill in each blank with the...Ch. 1.3 - In Exercises 5—10, fill in each blank with the...Ch. 1.3 - In Exercises 5—10, fill in each blank with the...Ch. 1.3 - In Exercises 5—10, fill in each blank with the...Ch. 1.3 - In Exercises 5—10, fill in each blank with the...Ch. 1.3 - In Exercise 11—16, determine whether the...Ch. 1.3 - In Exercise 11—16, determine whether the...Ch. 1.3 - In Exercise 11—16, determine whether the...Ch. 1.3 - In Exercise 11—16, determine whether the...Ch. 1.3 - In Exercise 11—16, determine whether the...Ch. 1.3 - In Exercise 11—16, determine whether the...Ch. 1.3 - To determine the effectiveness of a new pain...Ch. 1.3 - A medical researcher wants to determine whether...Ch. 1.3 - A medical researcher wants to determine whether...Ch. 1.3 - An agricultural scientist wants to determine the...Ch. 1.3 - Air pollution and colds: A scientist wants to...Ch. 1.3 - Cold medications: A scientist wants to determine...Ch. 1.3 - Taxicabs and crime: A sociologist discovered that...Ch. 1.3 - Recovering from heart attacks: In a study of...Ch. 1.3 - Eat your vegetables: In an observational study,...Ch. 1.3 - Vocabulary and height: A vocabulary test was given...Ch. 1.3 - Secondhand smoke: A recent study compared the...Ch. 1.3 - Pollution in China: In a recent study, Z. Zhao and...Ch. 1.3 - The Salk Vaccine Trial: In 1954, the first vaccine...Ch. 1.3 - Another Salk Vaccine Trial: Another study of the...Ch. 1.3 - Smoking and health: A study was performed by the...Ch. 1.3 - Alcohol and liver disease: It is known that...Ch. 1.4 - In Exercises 3—5, fill in each blank with the...Ch. 1.4 - In Exercises 3—5, fill in each blank with the...Ch. 1.4 - In Exercises 3—5, fill in each blank with the...Ch. 1.4 - In Exercises 6—8, determine whether the...Ch. 1.4 - In Exercises 6—8, determine whether the...Ch. 1.4 - In Exercises 6—8, determine whether the...Ch. 1.4 - In Exercises 9—16, specify the type of bias...Ch. 1.4 - In Exercises 9—16, specify the type of bias...Ch. 1.4 - In Exercises 9—16, specify the type of bias...Ch. 1.4 - In Exercises 9—16, specify the type of bias...Ch. 1.4 - In Exercises 9—16, specify the type of bias...Ch. 1.4 - In Exercises 9—16, specify the type of bias...Ch. 1.4 - In Exercises 9—16, specify the type of bias...Ch. 1.4 - In Exercises 9—16, specify the type of bias...Ch. 1.4 - Nuclear power, anyone? In a survey conducted by...Ch. 1.4 - Whos calling, please? Random-digit dialing is a...Ch. 1.4 - Whos calling, please? Many polls are conducted...Ch. 1.4 - Order of choices: When multiple-choice questions...Ch. 1.4 - Literary Digest poll: In the 1936 presidential...Ch. 1 - Provide an example of a qualitative variable and...Ch. 1 - Is the name of your favorite author a qualitative...Ch. 1 - Prob. 3CQCh. 1 - Prob. 4CQCh. 1 - True or false: Ideally, a sample should represent...Ch. 1 - Prob. 6CQCh. 1 - Prob. 7CQCh. 1 - Prob. 8CQCh. 1 - Prob. 9CQCh. 1 - Prob. 10CQCh. 1 - Prob. 11CQCh. 1 - Prob. 12CQCh. 1 - In analyzing the course grades of students in an...Ch. 1 - Prob. 14CQCh. 1 - Prob. 15CQCh. 1 - Prob. 1RECh. 1 - Prob. 2RECh. 1 - Prob. 3RECh. 1 - Prob. 4RECh. 1 - In Exercises 5—8, identify the kind of sample...Ch. 1 - Prob. 6RECh. 1 - Prob. 7RECh. 1 - Prob. 8RECh. 1 - Fluoride and tooth decay: Researchers examine the...Ch. 1 - Better gas mileage: A taxi company in a large city...Ch. 1 - Prob. 11RECh. 1 - Prob. 12RECh. 1 - Prob. 13RECh. 1 - Prob. 14RECh. 1 - Prob. 15RECh. 1 - Describe the difference between a stratified...Ch. 1 - Prob. 2WAICh. 1 - Describe circumstances under which each of the...Ch. 1 - Suppose that you were asked to collect some...Ch. 1 - Prob. 5WAICh. 1 - What are the primary differences between a...Ch. 1 - What are the advantages of a double-blind study?...Ch. 1 - Prob. 8WAICh. 1 - Prob. 9WAICh. 1 - Air pollution is a serious problem in many places....Ch. 1 - Prob. 2CSCh. 1 - Air pollution is a serious problem in many places....Ch. 1 - Air pollution is a serious problem in many places....Ch. 1 - Air pollution is a serious problem in many places....Ch. 1 - Air pollution is a serious problem in many places....Ch. 1 - Is there a large difference between the percentage...Ch. 1 - Explain why the percentage of high-exposure people...Ch. 1 - Explain why the percentage of low-exposure people...Ch. 1 - As the weather sets warmer. PM goes down because...Ch. 1 - It is generally the case in epidemiologic studies...Ch. 1 - Rather than send out questionnaires, the...
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