STAT 121 Exam Questions Verified Answers
Latest Update 2025
What is the mean of the sampling distribution of p̂ ?
A. The mean equals p̂ ,which is 66%.
B. The mean equals p, which is 66%.
C. The mean will equal p, but we don't know what the value of p is.p - ANS B. The mean equals
p, which is 66%.
In the 2004 election in Utah, 66% of all Utah voters voted for Amendment 3, the marriage
amendment. Suppose a Statistics major decided to predict the sampling distribution of p̂ for
samples of size 100 for this situation.
What is the probability of getting a sample proportion, p̂ ,from an SRS of 100 Utah voters
between 0.6 and 0.7?
A. 0.6975
B. 0.0985
C. 0.7995
D. 0.1020 - ANS A. 0.6975
,In the 2004 election in Utah, 66% of all Utah voters voted for Amendment 3, the marriage
amendment. Suppose a Statistics major decided to predict the sampling distribution of p̂ for
samples of size 100 for this situation.
What is the standard deviation of the sampling distribution of p̂ ?
A. 0.00660
B. 0.00224
C. 0.66000
D. 0.04737 - ANS D. 0.04737
In the 2004 election in Utah, 66% of all Utah voters voted for Amendment 3, the marriage
amendment. Suppose a Statistics major decided to predict the sampling distribution of p̂ for
samples of size 100 for this situation.
What would happen to the mean of the sampling distribution of p̂ if the Statistics major
predicted the sampling distribution of p̂ for samples of size 500 instead of size 100?
A. The mean would increase.
B. The mean would stay the same.
C. The mean would decrease. - ANS B. The mean would stay the same.
In the 2004 election in Utah, 66% of all Utah voters voted for Amendment 3, the marriage
amendment. Suppose a Statistics major decided to predict the sampling distribution of p̂ for
samples of size 100 for this situation.
,What would happen to the shape of the sampling distribution of p̂ if samples of size 500 were
taken instead of samples of size 100?
A. The shape would stay the same.
B. The shape would be closer to Normal.
C. The shape would be farther from Normal. - ANS B. The shape would be closer to Normal.
In the 2004 election in Utah, 66% of all Utah voters voted for Amendment 3, the marriage
amendment. Suppose a Statistics major decided to predict the sampling distribution of p̂ for
samples of size 100 for this situation.
What would happen to the standard deviation of the sampling distribution of p̂ if samples of
size 500 were taken instead of samples of size 100?
A. The standard deviation would increase.
B. The standard deviation would stay the same.
C. The standard deviation would decrease. - ANS C. The standard deviation would decrease.
True or False: Shape, center, and spread have no meaning for bar graphs
True
False - ANS TRUE
What type of graph would work best for displaying the majors of 2000 college
freshman? A. Boxplot
, B. Stem plot
C. Bar chart
D. Histogram - ANS C. Bar chart
In a telephone survey, drivers were asked, "Recalling the last ten traffic lights you drove
through, how many were red when you entered the intersection?" What type of variable
is "number of traffic lights that were red"?
A. Categorical
B. Quantitative - ANS B. Quantitative
What type of variable is "whether a driver entered the intersection when the light was red at
his/her last stop light"?
A. Categorical
B. Quantitative - ANS A. Categorical
True or False: If the population proportion is 0.04, the sampling distribution of p̂ for samples of
size 100 will be approximately Normal. - ANS FALSE
In 2012, 21% of BYU undergraduates were married. Using a sample size of 200, what is the
mean of the sampling distribution of p̂ ?
A.
The mean is equal to p, which is 21% or 0.21.
B.
Latest Update 2025
What is the mean of the sampling distribution of p̂ ?
A. The mean equals p̂ ,which is 66%.
B. The mean equals p, which is 66%.
C. The mean will equal p, but we don't know what the value of p is.p - ANS B. The mean equals
p, which is 66%.
In the 2004 election in Utah, 66% of all Utah voters voted for Amendment 3, the marriage
amendment. Suppose a Statistics major decided to predict the sampling distribution of p̂ for
samples of size 100 for this situation.
What is the probability of getting a sample proportion, p̂ ,from an SRS of 100 Utah voters
between 0.6 and 0.7?
A. 0.6975
B. 0.0985
C. 0.7995
D. 0.1020 - ANS A. 0.6975
,In the 2004 election in Utah, 66% of all Utah voters voted for Amendment 3, the marriage
amendment. Suppose a Statistics major decided to predict the sampling distribution of p̂ for
samples of size 100 for this situation.
What is the standard deviation of the sampling distribution of p̂ ?
A. 0.00660
B. 0.00224
C. 0.66000
D. 0.04737 - ANS D. 0.04737
In the 2004 election in Utah, 66% of all Utah voters voted for Amendment 3, the marriage
amendment. Suppose a Statistics major decided to predict the sampling distribution of p̂ for
samples of size 100 for this situation.
What would happen to the mean of the sampling distribution of p̂ if the Statistics major
predicted the sampling distribution of p̂ for samples of size 500 instead of size 100?
A. The mean would increase.
B. The mean would stay the same.
C. The mean would decrease. - ANS B. The mean would stay the same.
In the 2004 election in Utah, 66% of all Utah voters voted for Amendment 3, the marriage
amendment. Suppose a Statistics major decided to predict the sampling distribution of p̂ for
samples of size 100 for this situation.
,What would happen to the shape of the sampling distribution of p̂ if samples of size 500 were
taken instead of samples of size 100?
A. The shape would stay the same.
B. The shape would be closer to Normal.
C. The shape would be farther from Normal. - ANS B. The shape would be closer to Normal.
In the 2004 election in Utah, 66% of all Utah voters voted for Amendment 3, the marriage
amendment. Suppose a Statistics major decided to predict the sampling distribution of p̂ for
samples of size 100 for this situation.
What would happen to the standard deviation of the sampling distribution of p̂ if samples of
size 500 were taken instead of samples of size 100?
A. The standard deviation would increase.
B. The standard deviation would stay the same.
C. The standard deviation would decrease. - ANS C. The standard deviation would decrease.
True or False: Shape, center, and spread have no meaning for bar graphs
True
False - ANS TRUE
What type of graph would work best for displaying the majors of 2000 college
freshman? A. Boxplot
, B. Stem plot
C. Bar chart
D. Histogram - ANS C. Bar chart
In a telephone survey, drivers were asked, "Recalling the last ten traffic lights you drove
through, how many were red when you entered the intersection?" What type of variable
is "number of traffic lights that were red"?
A. Categorical
B. Quantitative - ANS B. Quantitative
What type of variable is "whether a driver entered the intersection when the light was red at
his/her last stop light"?
A. Categorical
B. Quantitative - ANS A. Categorical
True or False: If the population proportion is 0.04, the sampling distribution of p̂ for samples of
size 100 will be approximately Normal. - ANS FALSE
In 2012, 21% of BYU undergraduates were married. Using a sample size of 200, what is the
mean of the sampling distribution of p̂ ?
A.
The mean is equal to p, which is 21% or 0.21.
B.
