STAT 200 EXAM 2 SCRIPT 2026 COMPLETE
ANSWERS VERIFIED
◉ _______refers to randomly selecting participants from the
population.
________ refers to randomly assigning participants to different groups.
Answer: Random sampling, Randomization
◉ Do Penn State freshmen or sophomores tend to weigh more?
We could take a random sample of Penn State freshmen and weigh
them. Then, wait a year until they are sophomores and weigh them
each a second time. In this study, the cases are_______. Or, we could
take a random sample of Penn State freshmen and a random sample
of Penn State sophomores and weigh each student. In this study, the
cases are______ Answer: matched, not matched
◉ In one study a sample of students who have taken both STAT 200
and MATH 220 was obtained. Each student's STAT 200 score was
compared to their MATH 200 score. In this study the samples are
______ . In a second study a sample of students who are only enrolled
in STAT 200 was obtained as well as a sample of students who are
only enrolled in MATH 220. The average final grade of students in
STAT 200 was compared to the average final grade of the students in
MATH 220. In this study the samples are _______ . Answer: paired,
independent
,◉ A. Describe a research study in which a single-blind design should
be used (as opposed to double-blind or no blinding).
B. Clearly explain why the single-blind design is appropriate in this
specific scenario. Answer: If a tomato sauce company was trying to
determine if customers would prefer their sauces over their
competitor's sauce. The company can have a taste testing at a
grocery store where customers were given two different kinds of
tomato sauce without knowing which brand it was from. The single-
blind method is perfect to determine which tomato sauce people
prefer to buy because since the customer doesn't know the brand of
the sauce their answers to which sauce tastes the best for them will
be unbias.
◉ Which of the following variables are quantitative?
Select all that apply.
a. age in months
b. favorite color
c. name
d. weight in kg Answer: a, d
◉ If there is a 60% chance of rain tomorrow, what are the odds that
it will rain tomorrow?
a. 0.40 to 1
b. 0.60 to 1
, c. 1 to 1
d. 1.5 to 1 Answer: d
◉ P(A) = 0.53
Compute the complement of P(A). Answer: 0.47
◉ A scale is normally distributed with a mean of 50 and standard
deviation of 10. According to the Empirical Rule, between what two
values should we expect the middle 95% of observations to fall?
a. [10,90]
b. [20,80]
c. [30, 70]
d. [40, 60] Answer: c
◉ Scores on a quiz are normally distributed with a mean of 10.2 and
a standard deviation of 2.3.
Compute the z score for a quiz score of 14. Round your final answer
to three decimal places. Answer: 1.652
◉ Given μ = 400 and σ = 50, compute the z score for an observation
of x i =356
Round your final answer to three decimal places. Answer: -0.88
ANSWERS VERIFIED
◉ _______refers to randomly selecting participants from the
population.
________ refers to randomly assigning participants to different groups.
Answer: Random sampling, Randomization
◉ Do Penn State freshmen or sophomores tend to weigh more?
We could take a random sample of Penn State freshmen and weigh
them. Then, wait a year until they are sophomores and weigh them
each a second time. In this study, the cases are_______. Or, we could
take a random sample of Penn State freshmen and a random sample
of Penn State sophomores and weigh each student. In this study, the
cases are______ Answer: matched, not matched
◉ In one study a sample of students who have taken both STAT 200
and MATH 220 was obtained. Each student's STAT 200 score was
compared to their MATH 200 score. In this study the samples are
______ . In a second study a sample of students who are only enrolled
in STAT 200 was obtained as well as a sample of students who are
only enrolled in MATH 220. The average final grade of students in
STAT 200 was compared to the average final grade of the students in
MATH 220. In this study the samples are _______ . Answer: paired,
independent
,◉ A. Describe a research study in which a single-blind design should
be used (as opposed to double-blind or no blinding).
B. Clearly explain why the single-blind design is appropriate in this
specific scenario. Answer: If a tomato sauce company was trying to
determine if customers would prefer their sauces over their
competitor's sauce. The company can have a taste testing at a
grocery store where customers were given two different kinds of
tomato sauce without knowing which brand it was from. The single-
blind method is perfect to determine which tomato sauce people
prefer to buy because since the customer doesn't know the brand of
the sauce their answers to which sauce tastes the best for them will
be unbias.
◉ Which of the following variables are quantitative?
Select all that apply.
a. age in months
b. favorite color
c. name
d. weight in kg Answer: a, d
◉ If there is a 60% chance of rain tomorrow, what are the odds that
it will rain tomorrow?
a. 0.40 to 1
b. 0.60 to 1
, c. 1 to 1
d. 1.5 to 1 Answer: d
◉ P(A) = 0.53
Compute the complement of P(A). Answer: 0.47
◉ A scale is normally distributed with a mean of 50 and standard
deviation of 10. According to the Empirical Rule, between what two
values should we expect the middle 95% of observations to fall?
a. [10,90]
b. [20,80]
c. [30, 70]
d. [40, 60] Answer: c
◉ Scores on a quiz are normally distributed with a mean of 10.2 and
a standard deviation of 2.3.
Compute the z score for a quiz score of 14. Round your final answer
to three decimal places. Answer: 1.652
◉ Given μ = 400 and σ = 50, compute the z score for an observation
of x i =356
Round your final answer to three decimal places. Answer: -0.88
