TO ACCOMPANY
UNDERSTANDING BASIC STATISTICS
FOURTH EDITION BRASE/BRASE
Charles Hen ry Brase
Regis University
Corrinne Pellillo Brase
Arapahoe Community College
business exams, often requiring students to demonstrate knowledge of legal statutes, case law, and their ability to apply legal reasoning. Common types of law exams include:Essay
Laurel Tech Integrated Publishing Services
Printed in the U.S.A.
ISBN 13: 978-0-618-63229-9
ISBN 10: 0-618-63229-8
, Contents
Chapter 1 Getting Started 1
Chapter 2 Organizing Data 4
Chapter 3 Averages ad Variation 17
Chapter 4 Correlation and Regression 26
Chapter 5 Elementary Probability Theory 35
Chapter 6 Binomial Probability Distribution and Related Topics 45
Chapter 7 Normal Curves and Sampling Distribution 57
Chapter 8 Estimation 77
Chapter 9 Hypothesis Testing 88
Chapter 10 Inferences About Differences 105
Chapter 11 Additional Topics Using Inference 126
business exams, often requiring students to demonstrate knowledge of legal statutes, case law, and their ability to apply legal reasoning. Common types of law exams include:Essay
, Chapter 1 Getting Started
Section 1.1
business exams, often requiring students to demonstrate knowledge of legal statutes, case law, and their ability to apply legal reasoning. Common types of law exams include:Essay
1. (a) The variable is the response regarding frequency of eating at fast-food restaurants.
(b) The variable is qualitative. The categories are the number of times one eats in fast-
food restaurants.
(c) The implied population is responses for all adults in the U.S.
3. (a) The variable is student/faculty ratio at colleges.
(b) The variable is quantitative because arithmetic operations can be applied to the
ratios.
(c) The implied population is student/faculty ratio at all colleges in the nation.
5. (a) The variable is the nitrogen concentration (mg nitrogen/I water).
(b) The variable is quantitative because arithmetic operations can be applied to the time
intervals.
(c) The implied population is the nitrogen concentration (mg nitrogen/I water) in the
entire lake.
7. (a) length of time to complete an exam is a ratio level of measurement. The data may
be arranged in order, differences and ratios are meaningful, and a time of 0 is the
starting point for all measurements.
(b) Time offirst class is an interval level of measurement. The data may be arranged in
order and differences are meaningful.
(c) Major field of study is a nominal level of measurement. The data consists of names
only.
(d) Course evaluation scale is an ordinal level of measurement. The data may be
arranged in order.
(e) Score on last exam is a ratio level of measurement. The data may be arranged in
order, differences and ratios are meaningful, and a score of 0 is the starting point
for all measurements.
(t) Age of student is a ratio level of measurement. The data may be arranged in order,
differences and ratios are meaningful, and an age of 0 is the starting point for all
measurements.
9. (a) Species offish is a nominal level of measurement. Data consist of names only.
(b) Cost of rod and reel is a ratio level of measurement. The data may be arranged in
order, differences and ratios are meaningful, and a cost of 0 is the starting point for
all measurements.
(c) Time of return home is an interval level of measurement. The data may be
arranged in order and differences are meaningful.
(d) Guidebook rating is an ordinal level of measurement. Data may be arranged in order.
(e) Number offish caught is a ratio level of measurement. The data may be arranged in
order, differences and ratios are meaningful, and 0 fish caught is the starting point
for all measurements.
(t) Temperature of the water is an interval level of measurement. The data may be
arranged in order and differences are meaningful.
, Section 1.2
1. Essay
3. Answers vary. Use groups of 4 digits.
5. (a) Yes, it is appropriate that the same n umber appears more than once because the
outcome of a die roll can repeat. The outcome of the 4th roll is 2.
(b) No, we do not expect the same sequence because the process is random.
7. (11) Reasons may vary. For instance, the first four students may make a special effort
to get to class on time.
(b) Reasons may vary. For instance, four students who come in late might all be
nursing students enrolled in an anatomy and physiology class that meets the hour
before in a far-away building. They may be more motivated than other students to
complete a degree requirement.
(c) Reasons may vary. For instance, four students sitting in the back row might
be less inclined to partici pate in class discussions. ·
(d) Reasons may vary. For instance, the tallest students might all be male.
9. Answers vary. Use singl e digits with correct answer placed in corresponding position.
11. (a) This technique is simple random sampling. Every sample of size n from the
population has an equal chance of being selected and every member of the
population has an equal chance of being included in the sample.
(b) This techniq ue is cluster sampling. The state, Hawaii, is divided into regions
using, say, the first 3 digits of the Zip code. Within each region a random sample
of 10 Zip code areas is selected using, say, all 5 digits of the Zip code. Then,
within each selected Zip codes, all businesses are surveyed. The sampling units,
defined by 5 digit Zip codes, are clusters of businesses, and within each selected
Zip code, the benefits package the businesses offer their employees differs
business to business.
(c) This technique is convenience sampling. This technique uses results or data that are
conveniently and readily obtained.
(d) This technique is systematic sampling. Every k t1t element is incl uded in the sample.
(e) This technique is stratified sampling. The population was divided into strata ( I 0
business types), then a simple random sample was drawn from each stratum.
business exams, often requiring students to demonstrate knowledge of legal statutes, case law, and their ability to apply legal reasoning. Common types of
law exams include:Essay
Section 1.3
1. (a) This is an observational study because observations and measurements of
individuals are conducted in a way that doesn't change the response or the variable
being measured.
(b) This is an experiment because a treatment is deliberatel y imposed on the
individuals in order to observe a possible change in the response or variable being
measured.
(c) This is an experiment because a treatment is del iberatel y imposed on the
individuals in order to observe a possi ble change in the response or variable
being measured.