STATS 121 PRACTICE QUESTIONS WITH VERIFIED
ANSWERS
Which of the following can be considered a population? Select all that apply.
A) all students at BYU
B) all pigeons in Utah
C) some students from BYU's STAT121 class
D) None of these - Answers - A & B
The purpose of statistics is to convert data into useful information
true
false - Answers - true
Which of the following is a "false" statement about statistics?
A) Collecting data from the entire "population" may be impossible.
B) Statistical information is never misleading or misrepresented.
C) All statistical summaries and conclusions should be reported in context.
D) Publishing research results is not a part of the Big Picture of Statistics. - Answers - B
A student in STAT121 wants to estimate the proportion of students who got an A on the
STAT121 final exam from last semester. They asked 200 students who took the class
last semester what grade they got on their final exam score was and recorded whether
or not it was an A.
What is the population of interest?
A) the sample of 200 students
B) all BYU students
C) all students currently in STAT121
D) all students who took STAT121 last semester - Answers - D
A student in STAT121 wants to estimate the proportion of students who got an A on the
STAT121 final exam from last semester. They asked 200 students who took the class
last semester what grade they got on their final exam score was and recorded whether
or not it was an A.
In the scenario, what is the sample?
,A) a subset of students currently enrolled in STAT121
B) the 200 students interviewed
C) all students who took STAT121 last semester
D) all BYU students - Answers - B
Probability is the process of drawing conclusions about the sample based on population
data.
True
False - Answers - false, probability is the math that allows us to draw conclusions about
the population using sample information. The process of doing that is called "inference".
What is the final step in the Big Picture of Statistics?
A) Exploratory data analysis
B) Inference
C) Produce data
D) Probability - Answers - B
The field of statistics ends once we have collected all of our data.
True
False - Answers - False, Collecting data is just step 1 of the Big Picture of Statistics
The report about water quality included information on the water quality at swimming
beaches in California. Forty-five of these beaches were sampled to test whether they
failed to meet water quality standards.
What is the population?
A) all beaches in California
B) all swimming beaches in California
C) the 45 beaches that were sampled
D) all beaches that fail the water quality test - Answers - B
The report about water quality included information on the water quality at swimming
beaches in California. Forty-five of these beaches were sampled to test whether they
failed to meet water quality standards.
In the scenario, what is the sample?
A) all beaches in California
B) all swimming beaches in California
C) the 45 beaches that were sampled
D) the beaches that were sampled and failed the water quality test - Answers - C
Which of the following is not a valid probability sample?
A) a simple random sample
B) a stratified sample
C) a multistage sample
, D) a convenience sample - Answers - D
A reporter for the university newspaper wants to find out the opinions that all BYU
students have about the university health center. During a class break, he goes to the
health center, contacts a few students as they exit, and asks them to fill out a survey.
What type of sample is this?
A) a simple random sample
B) a stratified sample
C) a multistage sample
D) a convenience sample - Answers - D
Educators in California are concerned about a recent newspaper article reporting that
students in the United States are falling behind students in other nations in their math
skills. They decide to sample 10th grade students throughout the state and test their
mathematics skills. They first randomly select 10 school districts. From each of these 10
school districts they randomly select three high schools. From these 3 high schools they
randomly select 10 students and test them.
What type of sample is this?
A) a simple random sample
B) a stratified sample
C) a multistage sample
D) a convenience sample - Answers - C
Suppose a researcher is interested in the average ACT score for high school students
in Illinois. She randomly selects 150 high schools and then asks each student in the
selected high schools what their ACT score was.
What kind of sample is this?
A) simple random sample (SRS)
B) stratified sample
C) cluster sample
D) multistage sample - Answers - C
A popular magazine is interested in the average amount of time that their readers spend
on the internet each day. They randomly survey 100 of their female readers and 100 of
their male readers and ask them about their average internet use.
What type of sample is this?
A) a convenience sample
B) a volunteer sample
ANSWERS
Which of the following can be considered a population? Select all that apply.
A) all students at BYU
B) all pigeons in Utah
C) some students from BYU's STAT121 class
D) None of these - Answers - A & B
The purpose of statistics is to convert data into useful information
true
false - Answers - true
Which of the following is a "false" statement about statistics?
A) Collecting data from the entire "population" may be impossible.
B) Statistical information is never misleading or misrepresented.
C) All statistical summaries and conclusions should be reported in context.
D) Publishing research results is not a part of the Big Picture of Statistics. - Answers - B
A student in STAT121 wants to estimate the proportion of students who got an A on the
STAT121 final exam from last semester. They asked 200 students who took the class
last semester what grade they got on their final exam score was and recorded whether
or not it was an A.
What is the population of interest?
A) the sample of 200 students
B) all BYU students
C) all students currently in STAT121
D) all students who took STAT121 last semester - Answers - D
A student in STAT121 wants to estimate the proportion of students who got an A on the
STAT121 final exam from last semester. They asked 200 students who took the class
last semester what grade they got on their final exam score was and recorded whether
or not it was an A.
In the scenario, what is the sample?
,A) a subset of students currently enrolled in STAT121
B) the 200 students interviewed
C) all students who took STAT121 last semester
D) all BYU students - Answers - B
Probability is the process of drawing conclusions about the sample based on population
data.
True
False - Answers - false, probability is the math that allows us to draw conclusions about
the population using sample information. The process of doing that is called "inference".
What is the final step in the Big Picture of Statistics?
A) Exploratory data analysis
B) Inference
C) Produce data
D) Probability - Answers - B
The field of statistics ends once we have collected all of our data.
True
False - Answers - False, Collecting data is just step 1 of the Big Picture of Statistics
The report about water quality included information on the water quality at swimming
beaches in California. Forty-five of these beaches were sampled to test whether they
failed to meet water quality standards.
What is the population?
A) all beaches in California
B) all swimming beaches in California
C) the 45 beaches that were sampled
D) all beaches that fail the water quality test - Answers - B
The report about water quality included information on the water quality at swimming
beaches in California. Forty-five of these beaches were sampled to test whether they
failed to meet water quality standards.
In the scenario, what is the sample?
A) all beaches in California
B) all swimming beaches in California
C) the 45 beaches that were sampled
D) the beaches that were sampled and failed the water quality test - Answers - C
Which of the following is not a valid probability sample?
A) a simple random sample
B) a stratified sample
C) a multistage sample
, D) a convenience sample - Answers - D
A reporter for the university newspaper wants to find out the opinions that all BYU
students have about the university health center. During a class break, he goes to the
health center, contacts a few students as they exit, and asks them to fill out a survey.
What type of sample is this?
A) a simple random sample
B) a stratified sample
C) a multistage sample
D) a convenience sample - Answers - D
Educators in California are concerned about a recent newspaper article reporting that
students in the United States are falling behind students in other nations in their math
skills. They decide to sample 10th grade students throughout the state and test their
mathematics skills. They first randomly select 10 school districts. From each of these 10
school districts they randomly select three high schools. From these 3 high schools they
randomly select 10 students and test them.
What type of sample is this?
A) a simple random sample
B) a stratified sample
C) a multistage sample
D) a convenience sample - Answers - C
Suppose a researcher is interested in the average ACT score for high school students
in Illinois. She randomly selects 150 high schools and then asks each student in the
selected high schools what their ACT score was.
What kind of sample is this?
A) simple random sample (SRS)
B) stratified sample
C) cluster sample
D) multistage sample - Answers - C
A popular magazine is interested in the average amount of time that their readers spend
on the internet each day. They randomly survey 100 of their female readers and 100 of
their male readers and ask them about their average internet use.
What type of sample is this?
A) a convenience sample
B) a volunteer sample
