Bundle: Probability and Statistics for Engineering and the Sciences, Loose-leaf Version, 9th + WebAssign Printed Access Card, Multi-Term Courses
9th Edition
ISBN: 9780357099797
Author: DEVORE, Jay L.
Publisher: Cengage Learning
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Chapter 15.1, Problem 4E
A random sample of 15 automobile mechanics certified to work on a certain type of car was selected, and the time (in minutes) necessary for each one to diagnose a particular problem was determined, resulting in the following data:
Use the Wilcoxon test at significance level .10 to decide whether the data suggests that true average diagnostic time is less than 30 minutes.
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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.
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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 15 Solutions
Bundle: Probability and Statistics for Engineering and the Sciences, Loose-leaf Version, 9th + WebAssign Printed Access Card, Multi-Term Courses
Ch. 15.1 - Give as much information as you can about the...Ch. 15.1 - Here again is the data on expense ratio (%) for a...Ch. 15.1 - The accompanying data is a subset of the data...Ch. 15.1 - A random sample of 15 automobile mechanics...Ch. 15.1 - Both a gravimetric and a spectrophotometric method...Ch. 15.1 - Reconsider the situation described in Exercise 39...Ch. 15.1 - Use the large-sample version of the Wilcoxon test...Ch. 15.1 - Reconsider the port alcohol content data from...Ch. 15.1 - Prob. 9ECh. 15.2 - Prob. 10E
Ch. 15.2 - Prob. 11ECh. 15.2 - The article A Study of Wood Stove Particulate...Ch. 15.2 - The urinary fluoride concentration (parts per...Ch. 15.2 - Prob. 14ECh. 15.2 - The article Measuring the Exposure of Infants to...Ch. 15.2 - Prob. 16ECh. 15.3 - Prob. 17ECh. 15.3 - Compute the 99% signed-rank interval for true...Ch. 15.3 - Prob. 19ECh. 15.3 - Prob. 20ECh. 15.3 - Prob. 21ECh. 15.3 - Compute a 99% CI for 1 2 using the data in...Ch. 15.4 - The accompanying data refers to concentration of...Ch. 15.4 - Prob. 24ECh. 15.4 - Prob. 25ECh. 15.4 - Prob. 26ECh. 15.4 - In an experiment to study the way in which...Ch. 15 - The article Effects of a Rice-Rich Versus...Ch. 15 - Prob. 29SECh. 15 - The given data on phosphorus concentration in...Ch. 15 - Prob. 31SECh. 15 - Prob. 32SECh. 15 - The sign test is a very simple procedure for...Ch. 15 - Prob. 34SECh. 15 - Prob. 35SECh. 15 - Prob. 36SE
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