@PROFDOCDIGITALLIBRARIES
INSTRUCTOR’S
SOLUTIONS MANUAL
TONI GARCIA
Arizona State University
ELEMENTARY
STATISTICS
NINTH EDITION
Neil A. Weiss
School of Mathematical and
Statistical Sciences
Arizona State University
,@PROFDOCDIGITALLIBRARIES
Contents
Chapter 1 The Nature of Statistics 1
Chapter 2 Organizing Data 21
Chapter 3 Descriptive Measures 125
Chapter 4 Descriptive Methods in Regression
and Correlation 213
Chapter 5 Probability and Random Variables 295
Chapter 6 The Normal Distribution 359
Chapter 7 The Sampling Distribution of the
Sample Mean 413
Chapter 8 Confidence Intervals for One
Population Mean 473
Chapter 9 Hypothesis Tests for One
Population Mean 525
Chapter 10 Inferences for Two Population Means 567
Chapter 11 Inferences for Population Proportions 627
Chapter 12 Chi-Square Procedures 661
Chapter 13 Anaylsis of Variance (ANOVA) 713
Chapter 14 Inferential Methods in Regression
and Correlation 771
,@PROFDOCDIGITALLIBRARIES
CHAPTER 1 SOLUTIONS
Exercises 1.1
1.1 (a) The population is the collection of all individuals or items under
consideration in a statistical study.
(b) A sample is that part of the population from which information is
obtained.
1.2 The two major types of statistics are descriptive and inferential
statistics. Descriptive statistics consists of methods for organizing and
summarizing information. Inferential statistics consists of methods for
drawing and measuring the reliability of conclusions about a population
based on information obtained from a sample of the population.
1.3 Descriptive methods are used for organizing and summarizing information and
include graphs, charts, tables, averages, measures of variation, and
percentiles.
1.4 Descriptive statistics are used to organize and summarize information from a
sample before conducting an inferential analysis. Preliminary descriptive
analysis of a sample may reveal features of the data that lead to the
appropriate inferential method.
1.5 (a) An observational study is a study in which researchers simply observe
characteristics and take measurements.
(b) A designed experiment is a study in which researchers impose treatments
and controls and then observe characteristics and take measurements.
1.6 Observational studies can reveal only association, whereas designed
experiments can help establish causation.
1.7 This study is inferential. Data from a sample of Americans are used to make
an estimate of (or an inference about) average TV viewing time for all
Americans.
1.8 This study is descriptive. It is a summary of the average salaries in
professional baseball, basketball, and football for 2005 and 2011.
1.9 This study is descriptive. It is a summary of information on all homes sold
in different cities for the month of September 2012.
1.10 This study is inferential. National samples are used to make estimates of
(or inferences about) drug use throughout the entire nation.
1.11 This study is descriptive. It is a summary of the annual final closing
values of the Dow Jones Industrial Average at the end of December for the
years 2004-2013.
1.12 This study is inferential. Survey results were used to make percentage
estimates on which college majors were in demand among U.S firms for all
graduating college students.
1.13 (a) This study is inferential. It would have been impossible to survey all
U.S. adults about their opinions on Darwinism. Therefore, the data
must have come from a sample. Then inferences were made about the
opinions of all U.S. adults.
(b) The population consists of all U.S. adults. The sample consists only
of those U.S. adults who took part in the survey.
1.14 (a) The population consists of all U.S. adults. The sample consists of the
1000 U.S. adults who were surveyed.
(b) The percentage of 50% is a descriptive statistic since it describes the
opinion of the U.S. adults who were surveyed.
1.15 (a) The statement is descriptive since it only tells what was said by the
, 2 Chapter 1
respondents of the survey.
INSTRUCTOR’S
SOLUTIONS MANUAL
TONI GARCIA
Arizona State University
ELEMENTARY
STATISTICS
NINTH EDITION
Neil A. Weiss
School of Mathematical and
Statistical Sciences
Arizona State University
,@PROFDOCDIGITALLIBRARIES
Contents
Chapter 1 The Nature of Statistics 1
Chapter 2 Organizing Data 21
Chapter 3 Descriptive Measures 125
Chapter 4 Descriptive Methods in Regression
and Correlation 213
Chapter 5 Probability and Random Variables 295
Chapter 6 The Normal Distribution 359
Chapter 7 The Sampling Distribution of the
Sample Mean 413
Chapter 8 Confidence Intervals for One
Population Mean 473
Chapter 9 Hypothesis Tests for One
Population Mean 525
Chapter 10 Inferences for Two Population Means 567
Chapter 11 Inferences for Population Proportions 627
Chapter 12 Chi-Square Procedures 661
Chapter 13 Anaylsis of Variance (ANOVA) 713
Chapter 14 Inferential Methods in Regression
and Correlation 771
,@PROFDOCDIGITALLIBRARIES
CHAPTER 1 SOLUTIONS
Exercises 1.1
1.1 (a) The population is the collection of all individuals or items under
consideration in a statistical study.
(b) A sample is that part of the population from which information is
obtained.
1.2 The two major types of statistics are descriptive and inferential
statistics. Descriptive statistics consists of methods for organizing and
summarizing information. Inferential statistics consists of methods for
drawing and measuring the reliability of conclusions about a population
based on information obtained from a sample of the population.
1.3 Descriptive methods are used for organizing and summarizing information and
include graphs, charts, tables, averages, measures of variation, and
percentiles.
1.4 Descriptive statistics are used to organize and summarize information from a
sample before conducting an inferential analysis. Preliminary descriptive
analysis of a sample may reveal features of the data that lead to the
appropriate inferential method.
1.5 (a) An observational study is a study in which researchers simply observe
characteristics and take measurements.
(b) A designed experiment is a study in which researchers impose treatments
and controls and then observe characteristics and take measurements.
1.6 Observational studies can reveal only association, whereas designed
experiments can help establish causation.
1.7 This study is inferential. Data from a sample of Americans are used to make
an estimate of (or an inference about) average TV viewing time for all
Americans.
1.8 This study is descriptive. It is a summary of the average salaries in
professional baseball, basketball, and football for 2005 and 2011.
1.9 This study is descriptive. It is a summary of information on all homes sold
in different cities for the month of September 2012.
1.10 This study is inferential. National samples are used to make estimates of
(or inferences about) drug use throughout the entire nation.
1.11 This study is descriptive. It is a summary of the annual final closing
values of the Dow Jones Industrial Average at the end of December for the
years 2004-2013.
1.12 This study is inferential. Survey results were used to make percentage
estimates on which college majors were in demand among U.S firms for all
graduating college students.
1.13 (a) This study is inferential. It would have been impossible to survey all
U.S. adults about their opinions on Darwinism. Therefore, the data
must have come from a sample. Then inferences were made about the
opinions of all U.S. adults.
(b) The population consists of all U.S. adults. The sample consists only
of those U.S. adults who took part in the survey.
1.14 (a) The population consists of all U.S. adults. The sample consists of the
1000 U.S. adults who were surveyed.
(b) The percentage of 50% is a descriptive statistic since it describes the
opinion of the U.S. adults who were surveyed.
1.15 (a) The statement is descriptive since it only tells what was said by the
, 2 Chapter 1
respondents of the survey.
