STAT 121 Exam Questions Verified Answers Latest
Update 2025
α = ? - ANS 0.05
p* = ? - ANS O.5 (unless stated otherwise)
If a problem does not tell you the p*, what is it's value? - ANS 0.5
Below is a plot of data from a sample of 18 students. In this sample, the students were asked
their class standing. (If the graph is missing, refer to the pdf file of the credit quiz posted on
Learning Suite under the "Content" tab)
(Refer to Image a)
What is the shape of this plot?
A. Left skewed
B. Right Skewed
C. Symmetrical
D. Does not apply; the shape of a distribution only pertains to quantitative data - ANS D. Does
not apply; the shape of a distribution only pertains to quantitative data
Which graph is the best choice for categorical data?
A. Pie chart
,B. Histogram or stemplot
C. Bar graph - ANS C. Bar graph
In a study of religious practices among college students, a random sample of 127 students was
interviewed; 107 of the students said that they pray at least once in a while.
What is the numerical value of the statistic p̂ that estimates p?
A. 0.107
B. 0.127
C. 0.843
D. 1.187 - ANS C. 0.843
In a study of religious practices among college students, a random sample of 127 students was
interviewed; 107 of the students said that they pray at least once in a while.
Which of the following best describes the parameter p?
A. The proportion of all college students who believe in a higher power
B. The proportion of all college students who say they are religious
C. The proportion of all college students who say they pray at least once in a while
D. The proportion of all individuals in the population who are college students - ANS C. The
proportion of all college students who say they pray at least once in a while
,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 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.
Update 2025
α = ? - ANS 0.05
p* = ? - ANS O.5 (unless stated otherwise)
If a problem does not tell you the p*, what is it's value? - ANS 0.5
Below is a plot of data from a sample of 18 students. In this sample, the students were asked
their class standing. (If the graph is missing, refer to the pdf file of the credit quiz posted on
Learning Suite under the "Content" tab)
(Refer to Image a)
What is the shape of this plot?
A. Left skewed
B. Right Skewed
C. Symmetrical
D. Does not apply; the shape of a distribution only pertains to quantitative data - ANS D. Does
not apply; the shape of a distribution only pertains to quantitative data
Which graph is the best choice for categorical data?
A. Pie chart
,B. Histogram or stemplot
C. Bar graph - ANS C. Bar graph
In a study of religious practices among college students, a random sample of 127 students was
interviewed; 107 of the students said that they pray at least once in a while.
What is the numerical value of the statistic p̂ that estimates p?
A. 0.107
B. 0.127
C. 0.843
D. 1.187 - ANS C. 0.843
In a study of religious practices among college students, a random sample of 127 students was
interviewed; 107 of the students said that they pray at least once in a while.
Which of the following best describes the parameter p?
A. The proportion of all college students who believe in a higher power
B. The proportion of all college students who say they are religious
C. The proportion of all college students who say they pray at least once in a while
D. The proportion of all individuals in the population who are college students - ANS C. The
proportion of all college students who say they pray at least once in a while
,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 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.
