Solucionario Probabilidad Y Estadística Para Ingenieria Jay L. Devore 6 Edi
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Publicado: 24 de diciembre de 2012
Chapter 1: Overview and Descriptive Statistics
CHAPTER 1
Section 1.1
1.
a.
Houston Chronicle, Des Moines Register, Chicago Tribune, Washington Post
b.
Capital One, Campbell Soup, Merrill Lynch, Pulitzer
c.
Bill Jasper, Kay Reinke, Helen Ford, David Menedez
d.
1.78, 2.44, 3.5, 3.04
a.
29.1 yd., 28.3 yd., 24.7 yd., 31.0 yd.
b.
432, 196, 184, 321
c.
2.1,4.0, 3.2, 6.3
d.
0.07 g, 1.58 g, 7.1 g, 27.2 g
a.
In a sample of 100 VCRs, what are the chances that more than 20 need service while
under warrantee? What are the chances than none need service while still under
warrantee?
b.
What proportion of all VCRs of this brand and model will need service within the
warrantee period?
2.
3.
1
Chapter 1: Overview andDescriptive Statistics
4.
a.
b.
Concrete: All living U.S. Citizens, all mutual funds marketed in the U.S., all books
published in 1980.
Hypothetical: All grade point averages for University of California undergraduates
during the next academic year. Page lengths for all books published during the next
calendar year. Batting averages for all major league players during the next baseball
season.Concrete: Probability: In a sample of 5 mutual funds, what is the chance that all 5 have
rates of return which exceeded 10% last year?
Statistics:
If previous year rates-of-return for 5 mutual funds were 9.6, 14.5, 8.3, 9.9
and 10.2, can we conclude that the average rate for all funds was below 10%?
Conceptual: Probability: In a sample of 10 books to be published next year, how likely isit that the average number of pages for the 10 is between 200 and 250?
Statistics: If the sample average number of pages for 10 books is 227, can we be
highly confident that the average for all books is between 200 and 245?
5.
a.
No, the relevant conceptual population is all scores of all students who participate in the
SI in conjunction with this particular statistics course.
b.The advantage to randomly choosing students to participate in the two groups is that we
are more likely to get a sample representative of the population at large. If it were left to
students to choose, there may be a division of abilities in the two groups which could
unnecessarily affect the outcome of the experiment.
c.
If all students were put in the treatment group there would be noresults with which to
compare the treatments.
6.
One could take a simple random sample of students from all students in the California State
University system and ask each student in the sample to report the distance form their
hometown to campus. Alternatively, the sample could be generated by taking a stratified
random sample by taking a simple random sample from each of the 23 campusesand again
asking each student in the sample to report the distance from their hometown to campus.
Certain problems might arise with self reporting of distances, such as recording error or poor
recall. This study is enumerative because there exists a finite, identifiable population of
objects from which to sample.
7.
One could generate a simple random sample of all single family homes inthe city or a
stratified random sample by taking a simple random sample from each of the 10 district
neighborhoods. From each of the homes in the sample the necessary variables would be
collected. This would be an enumerative study because there exists a finite, identifiable
population of objects from which to sample.
2
Chapter 1: Overview and Descriptive Statistics
8.
a.
Numberobservations equal 2 x 2 x 2 = 8
b.
This could be called an analytic study because the data would be collected on an existing
process. There is no sampling frame.
a.
There could be several explanations for the variability of the measurements. Among
them could be measuring error, (due to mechanical or technical changes across
measurements), recording error, differences in weather...
CHAPTER 1
Section 1.1
1.
a.
Houston Chronicle, Des Moines Register, Chicago Tribune, Washington Post
b.
Capital One, Campbell Soup, Merrill Lynch, Pulitzer
c.
Bill Jasper, Kay Reinke, Helen Ford, David Menedez
d.
1.78, 2.44, 3.5, 3.04
a.
29.1 yd., 28.3 yd., 24.7 yd., 31.0 yd.
b.
432, 196, 184, 321
c.
2.1,4.0, 3.2, 6.3
d.
0.07 g, 1.58 g, 7.1 g, 27.2 g
a.
In a sample of 100 VCRs, what are the chances that more than 20 need service while
under warrantee? What are the chances than none need service while still under
warrantee?
b.
What proportion of all VCRs of this brand and model will need service within the
warrantee period?
2.
3.
1
Chapter 1: Overview andDescriptive Statistics
4.
a.
b.
Concrete: All living U.S. Citizens, all mutual funds marketed in the U.S., all books
published in 1980.
Hypothetical: All grade point averages for University of California undergraduates
during the next academic year. Page lengths for all books published during the next
calendar year. Batting averages for all major league players during the next baseball
season.Concrete: Probability: In a sample of 5 mutual funds, what is the chance that all 5 have
rates of return which exceeded 10% last year?
Statistics:
If previous year rates-of-return for 5 mutual funds were 9.6, 14.5, 8.3, 9.9
and 10.2, can we conclude that the average rate for all funds was below 10%?
Conceptual: Probability: In a sample of 10 books to be published next year, how likely isit that the average number of pages for the 10 is between 200 and 250?
Statistics: If the sample average number of pages for 10 books is 227, can we be
highly confident that the average for all books is between 200 and 245?
5.
a.
No, the relevant conceptual population is all scores of all students who participate in the
SI in conjunction with this particular statistics course.
b.The advantage to randomly choosing students to participate in the two groups is that we
are more likely to get a sample representative of the population at large. If it were left to
students to choose, there may be a division of abilities in the two groups which could
unnecessarily affect the outcome of the experiment.
c.
If all students were put in the treatment group there would be noresults with which to
compare the treatments.
6.
One could take a simple random sample of students from all students in the California State
University system and ask each student in the sample to report the distance form their
hometown to campus. Alternatively, the sample could be generated by taking a stratified
random sample by taking a simple random sample from each of the 23 campusesand again
asking each student in the sample to report the distance from their hometown to campus.
Certain problems might arise with self reporting of distances, such as recording error or poor
recall. This study is enumerative because there exists a finite, identifiable population of
objects from which to sample.
7.
One could generate a simple random sample of all single family homes inthe city or a
stratified random sample by taking a simple random sample from each of the 10 district
neighborhoods. From each of the homes in the sample the necessary variables would be
collected. This would be an enumerative study because there exists a finite, identifiable
population of objects from which to sample.
2
Chapter 1: Overview and Descriptive Statistics
8.
a.
Numberobservations equal 2 x 2 x 2 = 8
b.
This could be called an analytic study because the data would be collected on an existing
process. There is no sampling frame.
a.
There could be several explanations for the variability of the measurements. Among
them could be measuring error, (due to mechanical or technical changes across
measurements), recording error, differences in weather...
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