, Principles of Data Science
Chapter 2
Collecting and Preparing Data
Critical Thinking
[2.1, LO 2.1.1]
1. Megan is interested in opening a gaming center that utilizes virtual reality (VR) technology.
She wants to gauge the level of interest in VR gaming among the residents of her city. She plans
to conduct a survey using a random sampling method and then use this data to determine the
potential demand for a VR gaming center in her city. What is the nature of the collected data,
experimental or observational?
Solution: The nature of the collected data in Megan's survey would be observational.
Observational data is data collected by observing and recording information without any
intervention or manipulation on the part of the researcher. In Megan's case, she plans to
conduct a survey to gauge the level of interest in VR gaming among the residents of her city.
The survey participants will provide their opinions, preferences, and demographic information,
but Megan will not be manipulating any variables or imposing experimental conditions on
them. This indicates that the data collection is observational in nature.
[2.2, LO 2.2.2]
3. A high school is conducting a survey to understand the opinions of the school’s students
toward the food options available in the cafeteria. They have divided the student population
into four groups based on grade level (9th, 10th, 11th, 12th). A random sample of 60 students is
selected from each group and asked to rate the cafeteria food on a scale of 1–10. The results
are shown in this table.
Grade Level Number of Average Rating
Students
9th 60 8.1
10th 60 7.4
11th 60 6.3
12th 60 6.1
Table 2.11: High School Survey
What sampling technique was used to collect this data?
Solution: The sampling technique used to collect this data is stratified sampling. This method,
stratified sampling, helps to ensure that the opinions of students from each grade level are
represented in the overall results.
11/11/24 For more free, peer-reviewed, openly licensed resources visit OpenStax.org. 2
Chapter 2
Collecting and Preparing Data
Critical Thinking
[2.1, LO 2.1.1]
1. Megan is interested in opening a gaming center that utilizes virtual reality (VR) technology.
She wants to gauge the level of interest in VR gaming among the residents of her city. She plans
to conduct a survey using a random sampling method and then use this data to determine the
potential demand for a VR gaming center in her city. What is the nature of the collected data,
experimental or observational?
Solution: The nature of the collected data in Megan's survey would be observational.
Observational data is data collected by observing and recording information without any
intervention or manipulation on the part of the researcher. In Megan's case, she plans to
conduct a survey to gauge the level of interest in VR gaming among the residents of her city.
The survey participants will provide their opinions, preferences, and demographic information,
but Megan will not be manipulating any variables or imposing experimental conditions on
them. This indicates that the data collection is observational in nature.
[2.2, LO 2.2.2]
3. A high school is conducting a survey to understand the opinions of the school’s students
toward the food options available in the cafeteria. They have divided the student population
into four groups based on grade level (9th, 10th, 11th, 12th). A random sample of 60 students is
selected from each group and asked to rate the cafeteria food on a scale of 1–10. The results
are shown in this table.
Grade Level Number of Average Rating
Students
9th 60 8.1
10th 60 7.4
11th 60 6.3
12th 60 6.1
Table 2.11: High School Survey
What sampling technique was used to collect this data?
Solution: The sampling technique used to collect this data is stratified sampling. This method,
stratified sampling, helps to ensure that the opinions of students from each grade level are
represented in the overall results.
11/11/24 For more free, peer-reviewed, openly licensed resources visit OpenStax.org. 2
