Intro Stats, Books a la Carte Edition (5th Edition)
5th Edition
ISBN: 9780134210285
Author: Richard D. De Veaux, Paul Velleman, David E. Bock
Publisher: PEARSON
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Chapter 10, Problem 7E
Sampling A&M students For each scenario, identify the kind of sample used by the university administrators from Exercise 1:
- a) Select several dormitories at random and contact everyone living in the selected dorms.
- b) Using a computer-based list of registered students, contact 200 freshmen, 200 sophomores, 200 juniors, and 200 seniors selected at random from each class.
- c) Using a computer-based alphabetical list of registered students, select one of the first 25 on the list by random and then contact the student whose name is 50 names later, and then every 50 names beyond that.
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Example 4 (Part 2) We can use Statkey to take 50 different random samples of size 20 each, find the mean of
each sample, and compute a confidence interval for each one. The graph of the sampling distribution of the means
is on the left below, and that of the 50 confidence intervals is on the right.
1. What does each dot on the left hand dotplot represent?
StatKey Sampling Distribution for a Mean
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Sampling Dotplot of Mean
Left Tail Two-Tail Right Tail
60
50
40
40
30
20
20
10
samples = 50
mean = 41.626
std. error = 5.089
:
.:
:
::
0
25
30
35
40
45
50
55
60
41.626
Data Plots
Confidence Intervals
95%->
Confidence Intervals
Coverage
48/50 = 96%
20
40
60
80
2. Circle the confidence intervals that failed to capture the true mean.
3. Circle the sample means that produced those…
Example 4 (Part 1) One of the datasets in the Lock book
contains information about 215 countries of the world. One
of the variables is the percentage of people in the country
who have access to the internet. We have data for 203 of
those countries. The plot on the right shows a dotplot of
the data.
1. What are the cases?
Population
n = 203, mean = 43.024
median = 43.5, stdev = 29.259
20
2. What does each dot on the dotplot represent?
15
10
5
20
40
43.024
60
80
3. What type of data is do we collect from the cases, quantitative or categorical?
Let x be a random variable that represents the percentage of successful free throws a professional basketball player makes in a season. Let y be a random variable that represents the percentage of successful field goals a professional basketball player makes in a season. A random sample of n =6 professional basketball players gave the following information.
x
63
79
70
80
84
87
y
46
49
45
55
57
58
Find Se. Round your answer to three decimal places.
Chapter 10 Solutions
Intro Stats, Books a la Carte Edition (5th Edition)
Ch. 10.2 - Various claims are often made for surveys. Why is...Ch. 10.4 - We need to survey a random sample of the 300...Ch. 10 - Texas AM Administrators at Texas AM University...Ch. 10 - Satisfied workers The managers of a large company...Ch. 10 - AM again The president of the university plans a...Ch. 10 - Satisfied respondents The companys annual report...Ch. 10 - Sampling students A professor teaching a large...Ch. 10 - Sampling satisfaction A company hoping to assess...Ch. 10 - Sampling AM students For each scenario, identify...Ch. 10 - Satisfactory satisfaction samples For each...
Ch. 10 - Survey students What problems do you see with...Ch. 10 - Happy employees The company plans to have the head...Ch. 10 - Student samples The university administration of...Ch. 10 - Surveying employees The company of Exercise 2 is...Ch. 10 - Roper Through their Roper Reports Worldwide, GfK...Ch. 10 - Student center survey For their class project, a...Ch. 10 - Drug tests Major League Baseball tests players to...Ch. 10 - Gallup At its website (www.gallup.com), the Gallup...Ch. 10 - In Exercises 17 to 23, for the reports about...Ch. 10 - In Exercises 17 to 23, for the reports about...Ch. 10 - In Exercises 17 to 23, for the reports about...Ch. 10 - Prob. 20ECh. 10 - In Exercises 17 to 23, for the reports about...Ch. 10 - In Exercises 17 to 23, for the reports about...Ch. 10 - In Exercises 17 to 23, for the reports about...Ch. 10 - Mistaken poll A local TV station conducted a...Ch. 10 - Another mistaken poll Prior to the mayoral...Ch. 10 - Parent opinion, part 1 In a large city school...Ch. 10 - Parent opinion, part 2 Lets revisit the school...Ch. 10 - Prob. 28ECh. 10 - Prob. 29ECh. 10 - Roller coasters An amusement park has opened a new...Ch. 10 - Playground, act two The survey described in...Ch. 10 - Wording the survey Two members of the PTA...Ch. 10 - Banning ephedra An online poll on a website asked:...Ch. 10 - Survey questions Examine each of the following...Ch. 10 - More survey questions Examine each of the...Ch. 10 - Phone surveys Any time we conduct a survey, we...Ch. 10 - Cell phone survey What about drawing a random...Ch. 10 - Fuel economy Occasionally, when I fill my car with...Ch. 10 - Prob. 40ECh. 10 - Prob. 41ECh. 10 - Quality control Sammys Salsa, a small local...Ch. 10 - A fish story Concerned about reports of discolored...Ch. 10 - Prob. 44ECh. 10 - Prob. 45ECh. 10 - More sampling methods Consider each of these...
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