ALEKS 360 ELEM STATISTICS
10th Edition
ISBN: 9781264241385
Author: Bluman
Publisher: MCG
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Textbook Question
Chapter 1, Problem 10CQ
Select the best answer.
10. A researcher divided subjects into two groups according to gender and then selected members from each group for her sample. What sampling method was the researcher using?
a. Cluster
b. Random
c. Systematic
d. Stratified
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For unemployed persons in the United States, the average number of months of unemployment at the end of December 2009 was approximately seven months (Bureau of Labor Statistics, January 2010). Suppose the following data are for a particular region in upstate New York. The values in the first column show the number of
months unemployed and the values in the second column show the corresponding number of unemployed persons.
Months
Unemployed
Number
Unemployed
1
1029
2
1686
3
2269
4
2675
5
3487
6
4652
7
4145
8
3587
9
2325
10
1120
Let x be a random variable indicating the number of months a person is unemployed.
a. Use the data to develop an empirical discrete probability distribution for x (to 4 decimals).
(x)
f(x)
1
2
3
4
5
6
7
8
9
10
b. Show that your probability distribution satisfies the conditions for a valid discrete probability distribution.
The input in the box below will not be graded, but may be reviewed and considered by your instructor.
blank
c. What is the probability that a…
West Virginia has one of the highest divorce rates in the nation, with an annual rate of approximately 5 divorces per 1000 people (Centers for Disease Control and Prevention website, January 12, 2012). The Marital Counseling Center, Inc. (MCC) thinks that the high divorce rate in the state may require them to hire additional staff.
Working with a consultant, the management of MCC has developed the following probability distribution for x = the number of new clients for marriage counseling for the next year.
Excel File: data05-19.xls
x
10
f(x)
.05
20
30
.10
.10
40
.20
50
60
.35
.20
a. Is this probability distribution valid?
- Select your answer-
Explain.
f(x)
Σf(x)
Select your answer
Select your answer
b. What is the probability MCC will obtain more than 30 new clients (to 2 decimals)?
c. What is the probability MCC will obtain fewer than 20 new clients (to 2 decimals)?
d. Compute the expected value and variance of x.
Expected value
Variance
clients per year
squared clients per year
For unemployed persons in the United States, the average number of months of unemployment at the end of December 2009 was approximately seven months (Bureau of Labor Statistics, January 2010). Suppose the following data are for a particular region in upstate New York. The values in the first column show the number of
months unemployed and the values in the second column show the corresponding number of unemployed persons.
Months
Unemployed
Number
Unemployed
1
1029
2
1686
3
2269
4
2675
5
3487
6
4652
7
4145
8
3587
9
2325
10
1120
Let x be a random variable indicating the number of months a person is unemployed.
a. Use the data to develop an empirical discrete probability distribution for x (to 4 decimals).
(x)
f(x)
1
2
3
4
5
6
7
8
9
10
b. Show that your probability distribution satisfies the conditions for a valid discrete probability distribution.
The input in the box below will not be graded, but may be reviewed and considered by your instructor.
c. What is the probability that a person…
Chapter 1 Solutions
ALEKS 360 ELEM STATISTICS
Ch. 1.1 - Read the following on attendance and grades, and...Ch. 1.1 - Define statistics.Ch. 1.1 - What is a variable?Ch. 1.1 - What is meant by a census?Ch. 1.1 - How does a population differ from a sample?Ch. 1.1 - Explain the difference between descriptive and...Ch. 1.1 - Name three areas where probability is used.Ch. 1.1 - Why is information obtained from samples used more...Ch. 1.1 - What is meant by a biased sample?Ch. 1.1 - determine whether descriptive or inferential...
Ch. 1.1 - determine whether descriptive or inferential...Ch. 1.1 - determine whether descriptive or inferential...Ch. 1.1 - determine whether descriptive or inferential...Ch. 1.1 - determine whether descriptive or inferential...Ch. 1.1 - determine whether descriptive or inferential...Ch. 1.1 - determine whether descriptive or inferential...Ch. 1.1 - determine whether descriptive or inferential...Ch. 1.1 - determine whether descriptive or inferential...Ch. 1.2 - Applying the Concepts 1-2 Fatal Transportation...Ch. 1.2 - Explain the difference between qualitative...Ch. 1.2 - Prob. 2ECh. 1.2 - Why are continuous variables rounded when they are...Ch. 1.2 - Name and define the four types of measurement...Ch. 1.2 - determine whether the data are qualitative or...Ch. 1.2 - determine whether the data are qualitative or...Ch. 1.2 - determine whether the data are qualitative or...Ch. 1.2 - determine whether the data are qualitative or...Ch. 1.2 - determine whether the data are qualitative or...Ch. 1.2 - determine whether the data are qualitative or...Ch. 1.2 - determine whether the data are discrete or...Ch. 1.2 - determine whether the data are discrete or...Ch. 1.2 - determine whether the data are discrete or...Ch. 1.2 - determine whether the data are discrete or...Ch. 1.2 - determine whether the data are discrete or...Ch. 1.2 - determine whether the data are discrete or...Ch. 1.2 - give the boundaries of each value. 17. 24 feelCh. 1.2 - give the boundaries of each value. 18. 6.3...Ch. 1.2 - give the boundaries of each value. 19. 143 milesCh. 1.2 - give the boundaries of each value. 20. 19.63 tonsCh. 1.2 - give the boundaries of each value. 21. 200.7 milesCh. 1.2 - give the boundaries of each value. 22. 19 quartsCh. 1.2 - classify each as nominal-level, ordinal-level,...Ch. 1.2 - classify each as nominal-level, ordinal-level,...Ch. 1.2 - classify each as nominal-level, ordinal-level,...Ch. 1.2 - classify each as nominal-level, ordinal-level,...Ch. 1.2 - classify each as nominal-level, ordinal-level,...Ch. 1.2 - classify each as nominal-level, ordinal-level,...Ch. 1.2 - classify each as nominal-level, ordinal-level,...Ch. 1.2 - classify each as nominal-level, ordinal-level,...Ch. 1.3 - Applying the Concepts 13 American Culture and Drug...Ch. 1.3 - Name five ways that data can be collected.Ch. 1.3 - What is meant by sampling error and nonsampling...Ch. 1.3 - Why are random numbers used in sampling, and how...Ch. 1.3 - Name and define the four basic sampling methods.Ch. 1.3 - For Exercises 510, define a population that may...Ch. 1.3 - For Exercises 510, define a population that may...Ch. 1.3 - For Exercises 510, define a population that may...Ch. 1.3 - For Exercises 510, define a population that may...Ch. 1.3 - For Exercises 510, define a population that may...Ch. 1.3 - For Exercises 5-10, define a population that may...Ch. 1.3 - indentify the sampling method that was used. 11....Ch. 1.3 - indentify the sampling method that was used. 12....Ch. 1.3 - indentify the sampling method that was used. 13....Ch. 1.3 - indentify the sampling method that was used. 14....Ch. 1.3 - indentify the sampling method that was used. 15....Ch. 1.3 - indentify the sampling method that was used. 16....Ch. 1.4 - Todays Cigarettes Vapor or electronic cigarettes...Ch. 1.4 - Explain the difference between an observational...Ch. 1.4 - Prob. 2ECh. 1.4 - List some advantages and disadvantages of an...Ch. 1.4 - List some advantages and disadvantages of an...Ch. 1.4 - What is the difference between an experimental...Ch. 1.4 - What is the difference between independent...Ch. 1.4 - Why are a treatment group and a control group used...Ch. 1.4 - Explain the Hawthorne effect.Ch. 1.4 - What is a confounding variable?Ch. 1.4 - Define the placebo effect in a statistical study.Ch. 1.4 - Prob. 11ECh. 1.4 - Why do researchers use randomization in...Ch. 1.4 - Prob. 13ECh. 1.4 - Prob. 14ECh. 1.4 - determine whether an observational study or an...Ch. 1.4 - determine whether an observational study or an...Ch. 1.4 - determine whether an observational study or an...Ch. 1.4 - determine whether an observational study or an...Ch. 1.4 - identify the independent variable and the...Ch. 1.4 - identify the independent variable and the...Ch. 1.4 - Prob. 21ECh. 1.4 - Prob. 22ECh. 1.4 - Prob. 23ECh. 1.4 - Prob. 24ECh. 1.4 - Prob. 25ECh. 1.4 - suggest some confounding variables that the...Ch. 1.4 - For Exercises 2731, give a reason why the...Ch. 1.4 - Here is the whole truth about back pain.Ch. 1.4 - For Exercises 2731, give a reason why the...Ch. 1.4 - give a reason why the statement made might be...Ch. 1.4 - Prob. 31ECh. 1.4 - List the steps you should perform when conducting...Ch. 1.4 - Prob. 33ECh. 1.4 - Comment on the following statement, taken from a...Ch. 1.4 - In an ad for women, the following statement was...Ch. 1.4 - Prob. 36ECh. 1.4 - Prob. 37ECh. 1.4 - An ad for an exercise product stated: Using this...Ch. 1.4 - Prob. 39ECh. 1.4 - Just l capsule of Brand X can provide 24 hours of...Ch. 1.4 - Male children born to women who smoke during...Ch. 1.4 - Caffeine and Health In the 1980s, a study linked...Ch. 1 - state whether descriptive or inferential...Ch. 1 - state whether descriptive or inferential...Ch. 1 - state whether descriptive or inferential...Ch. 1 - state whether descriptive or inferential...Ch. 1 - state whether descriptive or inferential...Ch. 1 - state whether descriptive or inferential...Ch. 1 - state whether descriptive or inferential...Ch. 1 - state whether descriptive or inferential...Ch. 1 - classify each as nominal-level, ordinal-level,...Ch. 1 - Classify each as nominal-level, ordinal-level,...Ch. 1 - classify each as nominal-level, ordinal-level,...Ch. 1 - classify each as nominal-level, ordinal-level,...Ch. 1 - classify each as nominal-level, ordinal-level,...Ch. 1 - classify each as nominal-level, ordinal-level,...Ch. 1 - classify each as nominal-level, ordinal-level,...Ch. 1 - classify each as nominal-level, ordinal-level,...Ch. 1 - classify each as nominal-level, ordinal-level,...Ch. 1 - classify each as nominal-level, ordinal-level,...Ch. 1 - classify each variable as qualitative or...Ch. 1 - classify each variable as qualitative or...Ch. 1 - classify each variable as qualitative or...Ch. 1 - classify each variable as qualitative or...Ch. 1 - classify each variable as qualitative or...Ch. 1 - classify each variable as qualitative or...Ch. 1 - classify each variable as qualitative or...Ch. 1 - classify each variable as qualitative or...Ch. 1 - classify each variable as discrete or continuous....Ch. 1 - classify each variable as discrete or continuous....Ch. 1 - classify each variable as discrete or continuous....Ch. 1 - classify each variable as discrete or continuous....Ch. 1 - classify each variable as discrete or continuous....Ch. 1 - classify each variable as discrete or continuous....Ch. 1 - classify each variable as discrete or continuous....Ch. 1 - classify each variable as discrete or continuous....Ch. 1 - give the boundaries of each value. 35. 56 yards.Ch. 1 - give the boundaries of each value. 36. 105.4...Ch. 1 - give the boundaries of each value. 37. 72.6 tons.Ch. 1 - give the boundaries of each value. 38. 9.54...Ch. 1 - classify each sample as random, systematic,...Ch. 1 - classify each sample as random, systematic,...Ch. 1 - classify each sample as random, systematic,...Ch. 1 - classify each sample as random, systematic,...Ch. 1 - classify each sample as random, systematic,...Ch. 1 - classify each sample as random, systematic,...Ch. 1 - identify each study as being either observational...Ch. 1 - identify each study as being either observational...Ch. 1 - identify each study as being either observational...Ch. 1 - identify each study as being either observational...Ch. 1 - For Exercises 4952, identify the independent and...Ch. 1 - identify the independent and dependent variables...Ch. 1 - identify the independent and dependent variables...Ch. 1 - identify the independent and dependent variables...Ch. 1 - explain why the claims of these studies might be...Ch. 1 - explain why the claims of these studies might be...Ch. 1 - explain why the claims of these studies might be...Ch. 1 - For Exercises 5358, explain why the claims of...Ch. 1 - explain why the claims of these studies might be...Ch. 1 - explain why the claims of these studies might be...Ch. 1 - Determine whether each statement is true or false....Ch. 1 - Determine whether each statement is true or false....Ch. 1 - Prob. 3CQCh. 1 - Prob. 4CQCh. 1 - Prob. 5CQCh. 1 - The height of basketball players is considered a...Ch. 1 - Prob. 7CQCh. 1 - Prob. 8CQCh. 1 - Select the best answer. 9. What are the boundaries...Ch. 1 - Select the best answer. 10. A researcher divided...Ch. 1 - Prob. 11CQCh. 1 - Select the best answer. 12. A study that involves...Ch. 1 - Prob. 13CQCh. 1 - Two major branches of statistics are _____ and...Ch. 1 - Prob. 15CQCh. 1 - The group of all subjects under study is called...Ch. 1 - A group of subjects selected from the group of all...Ch. 1 - Three reasons why samples are used in statistics:...Ch. 1 - The four basic sampling methods are a. ______ b....Ch. 1 - Prob. 20CQCh. 1 - Prob. 21CQCh. 1 - For each statement, decide whether descriptive or...Ch. 1 - Classify each as nominal-level, ordinal-level,...Ch. 1 - Classify each variable as discrete or continuous....Ch. 1 - Give the boundaries of each. a. 32 minutes b. 0.48...
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- In Gallup's Annual Consumption Habits Poll, telephone interviews were conducted for a random sample of 1014 adults aged 18 and over. One of the questions was "How many cups of coffee, if any, do you drink on an average day?" The following table shows the results obtained (Gallup website, August 6, 2012). Excel File: data05-23.xls Number of Cups per Day Number of Responses 0 365 264 193 3 4 or more 91 101 Define a random variable x = number of cups of coffee consumed on an average day. Let x = 4 represent four or more cups. Round your answers to four decimal places. a. Develop a probability distribution for x. x 0 1 2 3 4 f(x) b. Compute the expected value of x. cups of coffee c. Compute the variance of x. cups of coffee squared d. Suppose we are only interested in adults that drink at least one cup of coffee on an average day. For this group, let y = the number of cups of coffee consumed on an average day. Compute the expected value of y. Compare it to the expected value of x. The…arrow_forwardIn Gallup's Annual Consumption Habits Poll, telephone interviews were conducted for a random sample of 1014 adults aged 18 and over. One of the questions was "How many cups of coffee, if any, do you drink on an average day?" The following table shows the results obtained (Gallup website, August 6, 2012). Excel File: data05-23.xls Number of Cups per Day Number of Responses 0 365 264 193 2 3 4 or more 91 101 Define a random variable x = number of cups of coffee consumed on an average day. Let x = 4 represent four or more cups. Round your answers to four decimal places. a. Develop a probability distribution for x. x 0 1 2 3 f(x) b. Compute the expected value of x. cups of coffee c. Compute the variance of x. cups of coffee squared d. Suppose we are only interested in adults that drink at least one cup of coffee on an average day. For this group, let y = the number of cups of coffee consumed on an average day. Compute the expected value of y. Compare it to the expected value of x. The…arrow_forwardA technician services mailing machines at companies in the Phoenix area. Depending on the type of malfunction, the service call can take 1, 2, 3, or 4 hours. The different types of malfunctions occur at about the same frequency. Develop a probability distribution for the duration of a service call. Duration of Call x f(x) 1 2 3 4 Which of the following probability distribution graphs accurately represents the data set? Consider the required conditions for a discrete probability function, shown below.Does this probability distribution satisfy equation (5.1)?Does this probability distribution satisfy equation (5.2)? What is the probability a service call will take three hours? A service call has just come in, but the type of malfunction is unknown. It is 3:00 P.M. and service technicians usually get off at 5:00 P.M. What is the probability the service technician will have to work overtime to fix the machine today?arrow_forward
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