TRY IT ANSWER GUIDE
OpenStax Introductory Business Statistics 2e
Answers to Try it Exercises
10/27/23 1
,OpenStax Introductory Business Statistics 2e
Answers to Try It Exercises
Table of Contents
Chapter 1
Chapter 2
Chapter 3
Chapter 4
Chapter 5
Chapter 6
Chapter 7
Chapter 8
Chapter 9
Chapter 10
Chapter 11
Chapter 12
Chapter 13
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,OpenStax Introductory Business Statistics 2e
Answers to Try it Exercises
Chapter 1 Sampling and Data
Section 1 Definition of Statistics, Probability, and Key Terms
TRY IT 1.1:
Determine what the key terms refer to in the following study. We want to know the average (mean)
amount of money spent on school uniforms each year by families with children at Knoll Academy. We
randomly survey 100 families with children in the school. Three of the families spent $65, $75, and $95,
respectively.
Solution:
The population is all families with children attending Knoll Academy.
The sample is a random selection of 100 families with children attending Knoll Academy.
The parameter is the average (mean) amount of money spent on school uniforms by families with
children at Knoll Academy.
The statistic is the average (mean) amount of money spent on school uniforms by families in the
sample.
The variable is the amount of money spent by one family. Let X = the amount of money spent on school
uniforms by one family with children attending Knoll Academy.
The data are the dollar amounts spent by the families. Examples of the data are $65, $75, and $95.
TRY IT 1.2:
Determine what key terms refer to in the following study.
A survey of athletes in a university was conducted to study the heights of athletes, in meters. Fill in the
letter of the phrase that best describes each of the items below.
1. Population ____
2. Statistics ____
3. Parameter ____
4. Sample ____
5. Variable ____
6. Data _____
a. the average height of athletes in the university
b. the average height of athletes in the survey
c. all athletes in the university
d. all students in the university
e. the height of one athlete
f. a group of athletes randomly selected
g. 1.82, 1.76, 1.69, 1.93
Solution:
1. c
2. b
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, OpenStax Introductory Business Statistics 2e
Answers to Try It Exercises
3. a
4. f
5. e
6. g
TRY IT 1.3:
Determine what the key terms refer to in the following study.
A survey is conducted to check the time taken by a mobile for charging of battery from 50% to 100%.
The criteria used to collect the data are:
Wattage of charger used Type of mobile used
30 W Android
We want to know the proportion of Android mobiles that are charged to 100% within 30 minutes. We
start with a simple random sample of 200 mobiles.
Solution:
The population is all Android mobiles.
The sample is the 200 mobiles, selected by a simple random sample.
The parameter is the proportion of Android mobiles that are charged to 100% within 30 minutes in the
population.
The statistic is the proportion of Android mobiles that are charged to 100% within 30 minutes in the
survey.
The variable X = the number of Android mobiles that are charged to 100% within 30 minutes.
The data are either: yes, charged to 100% within 30 minutes; or no, charged to 100% taking more than
30 minutes.
TRY IT 1.4:
Determine what the key terms refer to in the following study.
A study is to be conducted by a news agency to find the proportion of all truck drivers that have no
points on their license. The agency selects 1000 truck drivers randomly from the directory of truck
drivers and determines the number of truck drivers in the sample who have no points on their license.
Solution:
The population is all truck drivers present in the directory.
The parameter is the proportion of truck drivers that have no points on their license in the population.
The sample is the 1000 truck drivers selected randomly from the directory.
The statistics is the proportion of truck drivers that have no points on their license in the sample.
The variable X = the number of truck drivers that have no points on their license.
The data are either: yes, they have no points on their license; or no, they have points on their license.
Section 2 Data, Sampling, and Variation in Data and Sampling
TRY IT 1.5:
The data are the number of machines in a gym. You sample five gyms. One gym has 12 machines, one
gym has 15 machines, one gym has ten machines, one gym has 22 machines, and the other gym has 20
machines. What type of data is this?
11/02/23 4
OpenStax Introductory Business Statistics 2e
Answers to Try it Exercises
10/27/23 1
,OpenStax Introductory Business Statistics 2e
Answers to Try It Exercises
Table of Contents
Chapter 1
Chapter 2
Chapter 3
Chapter 4
Chapter 5
Chapter 6
Chapter 7
Chapter 8
Chapter 9
Chapter 10
Chapter 11
Chapter 12
Chapter 13
11/02/23 2
,OpenStax Introductory Business Statistics 2e
Answers to Try it Exercises
Chapter 1 Sampling and Data
Section 1 Definition of Statistics, Probability, and Key Terms
TRY IT 1.1:
Determine what the key terms refer to in the following study. We want to know the average (mean)
amount of money spent on school uniforms each year by families with children at Knoll Academy. We
randomly survey 100 families with children in the school. Three of the families spent $65, $75, and $95,
respectively.
Solution:
The population is all families with children attending Knoll Academy.
The sample is a random selection of 100 families with children attending Knoll Academy.
The parameter is the average (mean) amount of money spent on school uniforms by families with
children at Knoll Academy.
The statistic is the average (mean) amount of money spent on school uniforms by families in the
sample.
The variable is the amount of money spent by one family. Let X = the amount of money spent on school
uniforms by one family with children attending Knoll Academy.
The data are the dollar amounts spent by the families. Examples of the data are $65, $75, and $95.
TRY IT 1.2:
Determine what key terms refer to in the following study.
A survey of athletes in a university was conducted to study the heights of athletes, in meters. Fill in the
letter of the phrase that best describes each of the items below.
1. Population ____
2. Statistics ____
3. Parameter ____
4. Sample ____
5. Variable ____
6. Data _____
a. the average height of athletes in the university
b. the average height of athletes in the survey
c. all athletes in the university
d. all students in the university
e. the height of one athlete
f. a group of athletes randomly selected
g. 1.82, 1.76, 1.69, 1.93
Solution:
1. c
2. b
10/27/23 3
, OpenStax Introductory Business Statistics 2e
Answers to Try It Exercises
3. a
4. f
5. e
6. g
TRY IT 1.3:
Determine what the key terms refer to in the following study.
A survey is conducted to check the time taken by a mobile for charging of battery from 50% to 100%.
The criteria used to collect the data are:
Wattage of charger used Type of mobile used
30 W Android
We want to know the proportion of Android mobiles that are charged to 100% within 30 minutes. We
start with a simple random sample of 200 mobiles.
Solution:
The population is all Android mobiles.
The sample is the 200 mobiles, selected by a simple random sample.
The parameter is the proportion of Android mobiles that are charged to 100% within 30 minutes in the
population.
The statistic is the proportion of Android mobiles that are charged to 100% within 30 minutes in the
survey.
The variable X = the number of Android mobiles that are charged to 100% within 30 minutes.
The data are either: yes, charged to 100% within 30 minutes; or no, charged to 100% taking more than
30 minutes.
TRY IT 1.4:
Determine what the key terms refer to in the following study.
A study is to be conducted by a news agency to find the proportion of all truck drivers that have no
points on their license. The agency selects 1000 truck drivers randomly from the directory of truck
drivers and determines the number of truck drivers in the sample who have no points on their license.
Solution:
The population is all truck drivers present in the directory.
The parameter is the proportion of truck drivers that have no points on their license in the population.
The sample is the 1000 truck drivers selected randomly from the directory.
The statistics is the proportion of truck drivers that have no points on their license in the sample.
The variable X = the number of truck drivers that have no points on their license.
The data are either: yes, they have no points on their license; or no, they have points on their license.
Section 2 Data, Sampling, and Variation in Data and Sampling
TRY IT 1.5:
The data are the number of machines in a gym. You sample five gyms. One gym has 12 machines, one
gym has 15 machines, one gym has ten machines, one gym has 22 machines, and the other gym has 20
machines. What type of data is this?
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