INSTRUCTOR ANSWER GUIDE
OpenStax Introductory Business Statistics 2e
Instructor Answer Guide
,OpenStax Introductory Business Statistics 2e
Instructor Answer Guide
CHAPTER 1: SAMPLING AND DATA
Exercise 1. Identify: a. the population, b. the sample, c. the parameter, d. the statistic, e.
the variable, and f. the data. Give examples where appropriate.
A fitness center is interested in the mean amount of time a client exercises in
the center each week.
Solution a. The population is all of the clients of the fitness center.
b. A sample of the clients that use the fitness center for a given week.
c. The average amount of time that all clients exercise in one week.
d. The average amount of time that a sample of clients exercises in one week.
e. The amount of time that a client exercises in one week.
f. Examples are: 2 hours, 5 hours, and 7.5 hours
Exercise 2. Identify: a. the population, b. the sample, c. the parameter, d. the statistic, e.
the variable, and f. the data. Give examples where appropriate.
Ski resorts are interested in the mean age that children take their first ski and
snowboard lessons. They need this information to plan their ski classes
optimally.
Solution a. all children who take ski or snowboard lessons
b. a group of these children
c. the population mean age of children who take their first snowboard lesson
d. the sample mean age of children who take their first snowboard lesson
e. X = the age of one child who takes their first ski or snowboard lesson
f. values for X, such as 3, 7, and so on
Exercise 3. Identify: a. the population, b. the sample, c. the parameter, d. the statistic, e.
the variable, and f. the data. Give examples where appropriate.
A cardiologist is interested in the mean recovery period of her patients who
have had heart attacks.
Solution a. the cardiologist’s patients
b. a group of the cardiologist’s patients
c. the mean recovery period of all of the cardiologist’s patients
d. the mean recovery period of the group of the cardiologist’s patients
e. X = the mean recovery period of one patient
f. values for X, such as 10 days, 14 days, 20 days, and so on
Exercise 4. Identify: a. the population, b. the sample, c. the parameter, d. the statistic, e.
the variable, and f. the data. Give examples where appropriate.
Insurance companies are interested in the mean health costs each year of
their clients, so that they can determine the costs of health insurance.
Solution a. the clients of the insurance companies
2
October 28, 2025
, OpenStax Introductory Business Statistics 2e
Instructor Answer and Solution Guide
Chapter 1: Sampling and Data
b. a group of the clients
c. the mean health costs of the clients
d. the mean health costs of the sample
e. X = the health costs of one client
f. values for X, such as 34, 9, 82, and so on
Exercise 5. Identify: a. the population, b. the sample, c. the parameter, d. the statistic, e.
the variable, and f. the data. Give examples where appropriate.
A politician is interested in the proportion of voters in his district who think
he is doing a good job.
Solution a. all voters in the politician’s district
b. a random selection of voters in the politician’s district
c. the proportion of voters in this district who think this politician is doing a
good job
d. the proportion of voters in this district who think this politician is doing a
good job in the sample
e. X = the number of voters in the district who think this politician is doing a
good job
f. Yes, he is doing a good job. No, he is not doing a good job.
Exercise 6. Identify: a. the population, b. the sample, c. the parameter, d. the statistic, e.
the variable, and f. the data. Give examples where appropriate.
A marriage counselor is interested in the proportion of clients she counsels
who stay married.
Solution a. all the clients of this counselor
b. a group of clients of this marriage counselor
c. the proportion of all their clients who stay married
d. the proportion of the sample of the counselor’s clients who stay married
e. X = the number of couples who stay married
f. yes, no
Exercise 7. Identify: a. the population, b. the sample, c. the parameter, d. the statistic, e.
the variable, and f. the data. Give examples where appropriate.
Political pollsters may be interested in the proportion of people who will vote
for a particular cause.
Solution a. all voters (in a certain geographic area)
b. a random selection of all the voters
c. the proportion of voters who are interested in this particular cause
d. the proportion of voters who are interested in this particular cause in the
sample
e. X = the number of voters who are interested in this particular cause
f. yes, no
3
October 28, 2025
OpenStax Introductory Business Statistics 2e
Instructor Answer Guide
,OpenStax Introductory Business Statistics 2e
Instructor Answer Guide
CHAPTER 1: SAMPLING AND DATA
Exercise 1. Identify: a. the population, b. the sample, c. the parameter, d. the statistic, e.
the variable, and f. the data. Give examples where appropriate.
A fitness center is interested in the mean amount of time a client exercises in
the center each week.
Solution a. The population is all of the clients of the fitness center.
b. A sample of the clients that use the fitness center for a given week.
c. The average amount of time that all clients exercise in one week.
d. The average amount of time that a sample of clients exercises in one week.
e. The amount of time that a client exercises in one week.
f. Examples are: 2 hours, 5 hours, and 7.5 hours
Exercise 2. Identify: a. the population, b. the sample, c. the parameter, d. the statistic, e.
the variable, and f. the data. Give examples where appropriate.
Ski resorts are interested in the mean age that children take their first ski and
snowboard lessons. They need this information to plan their ski classes
optimally.
Solution a. all children who take ski or snowboard lessons
b. a group of these children
c. the population mean age of children who take their first snowboard lesson
d. the sample mean age of children who take their first snowboard lesson
e. X = the age of one child who takes their first ski or snowboard lesson
f. values for X, such as 3, 7, and so on
Exercise 3. Identify: a. the population, b. the sample, c. the parameter, d. the statistic, e.
the variable, and f. the data. Give examples where appropriate.
A cardiologist is interested in the mean recovery period of her patients who
have had heart attacks.
Solution a. the cardiologist’s patients
b. a group of the cardiologist’s patients
c. the mean recovery period of all of the cardiologist’s patients
d. the mean recovery period of the group of the cardiologist’s patients
e. X = the mean recovery period of one patient
f. values for X, such as 10 days, 14 days, 20 days, and so on
Exercise 4. Identify: a. the population, b. the sample, c. the parameter, d. the statistic, e.
the variable, and f. the data. Give examples where appropriate.
Insurance companies are interested in the mean health costs each year of
their clients, so that they can determine the costs of health insurance.
Solution a. the clients of the insurance companies
2
October 28, 2025
, OpenStax Introductory Business Statistics 2e
Instructor Answer and Solution Guide
Chapter 1: Sampling and Data
b. a group of the clients
c. the mean health costs of the clients
d. the mean health costs of the sample
e. X = the health costs of one client
f. values for X, such as 34, 9, 82, and so on
Exercise 5. Identify: a. the population, b. the sample, c. the parameter, d. the statistic, e.
the variable, and f. the data. Give examples where appropriate.
A politician is interested in the proportion of voters in his district who think
he is doing a good job.
Solution a. all voters in the politician’s district
b. a random selection of voters in the politician’s district
c. the proportion of voters in this district who think this politician is doing a
good job
d. the proportion of voters in this district who think this politician is doing a
good job in the sample
e. X = the number of voters in the district who think this politician is doing a
good job
f. Yes, he is doing a good job. No, he is not doing a good job.
Exercise 6. Identify: a. the population, b. the sample, c. the parameter, d. the statistic, e.
the variable, and f. the data. Give examples where appropriate.
A marriage counselor is interested in the proportion of clients she counsels
who stay married.
Solution a. all the clients of this counselor
b. a group of clients of this marriage counselor
c. the proportion of all their clients who stay married
d. the proportion of the sample of the counselor’s clients who stay married
e. X = the number of couples who stay married
f. yes, no
Exercise 7. Identify: a. the population, b. the sample, c. the parameter, d. the statistic, e.
the variable, and f. the data. Give examples where appropriate.
Political pollsters may be interested in the proportion of people who will vote
for a particular cause.
Solution a. all voters (in a certain geographic area)
b. a random selection of all the voters
c. the proportion of voters who are interested in this particular cause
d. the proportion of voters who are interested in this particular cause in the
sample
e. X = the number of voters who are interested in this particular cause
f. yes, no
3
October 28, 2025
