STT 231 Exam 1 & Exam 2 Combined: (Newest
2026/2027 Update) Questions and Verified
Answers | 100% Correct Grade A
STT 231 (Statistics for Scientists at MSU) Exam 1 covers exploratory data analysis,
data collection, sampling, and basic probability, while Exam 2 focuses on sampling
distributions, confidence intervals, and inference for population proportions/means.
Both exams aretypically closed-book, multiple-choice, roughly 25 questions, and test
application-focused knowledge using software output.
STT 231 Exam 1 Description: Exploratory Data Analysis. Pg….1
• Topics: Data types (quantitative vs. categorical), sampling methods, experimental
design, observational studies, and data visualization (histograms, boxplots,
scatterplots).
• Key Concepts: Describing distribution shapes (center/spread), mean/median
calculation, standard deviation, standardized scores (z-scores), and Chebyshev's rule.
• Regression: Interpreting scatterplots, correlation coefficients
and simple linear regression models (residuals,
STT 231 Exam 2 Description: Inference & Probability. Pg. …33
• Topics: Probability distributions (discrete, binomial, normal), sampling distributions,
confidence intervals, and hypothesis testing.
• Inference: Using confidence intervals to estimate population proportions or means,
and performing one-sample hypothesis tests.
• Key Concepts: P-value interpretation, Cohen's
effect size, Central Limit Theorem (CLT), and t-distributions.
STT 231 Exam 1
Quiz_________________?
1
, What makes up a data set? -
Answer
Data are made up of observational units (cases)
Quiz_________________?
Variable -
Answer
any characteristic or value recorded for each case; found in columns (vertical)
Quiz_________________?
Observations/Observational Units/Cases -
Answer
Found in rows (horizontal)
Quiz_________________?
Values -
Answer
Items that populate a data set
Quiz_________________?
All variables are either ______ or ______ -
2
, Answer
Categorical or numerical
Quiz_________________?
Categorical Variables -
Answer
Identify a case as a measure of a group, placing each case into exactly one of two
or more groups called levels.
Ex. An MSU student can be classified by their year (first second third...) where
these categories are called levels.
Quiz_________________?
Numerical Variables -
Answer
Measure a numerical quantity for each case. Unlike categorical variables,
numerical operations like adding and averaging make sense for these quantitative
variables.
Ex. we can record how many credits an MSU student has earned (1,2,3...)
Quiz_________________?
Numerical Variables can be divided into two groups: ____ and____ -
3
, Answer
Discrete and continuous
Quiz_________________?
Numerical discrete variables -
Answer
can only take on limited values in a variables domain.
Ex. How many siblings do I have? (1,2,3...) but could not say 1.7 siblings.
Quiz_________________?
Numerical Continuous Variables -
Answer
can take on any value in a variable's domain.
Ex. Height-- could be 52in or 53in or 53.262 in
Quiz_________________?
Categorical variables can be divided into 2 groups: ____ and ____ -
Answer
nominal and ordinal
4
2026/2027 Update) Questions and Verified
Answers | 100% Correct Grade A
STT 231 (Statistics for Scientists at MSU) Exam 1 covers exploratory data analysis,
data collection, sampling, and basic probability, while Exam 2 focuses on sampling
distributions, confidence intervals, and inference for population proportions/means.
Both exams aretypically closed-book, multiple-choice, roughly 25 questions, and test
application-focused knowledge using software output.
STT 231 Exam 1 Description: Exploratory Data Analysis. Pg….1
• Topics: Data types (quantitative vs. categorical), sampling methods, experimental
design, observational studies, and data visualization (histograms, boxplots,
scatterplots).
• Key Concepts: Describing distribution shapes (center/spread), mean/median
calculation, standard deviation, standardized scores (z-scores), and Chebyshev's rule.
• Regression: Interpreting scatterplots, correlation coefficients
and simple linear regression models (residuals,
STT 231 Exam 2 Description: Inference & Probability. Pg. …33
• Topics: Probability distributions (discrete, binomial, normal), sampling distributions,
confidence intervals, and hypothesis testing.
• Inference: Using confidence intervals to estimate population proportions or means,
and performing one-sample hypothesis tests.
• Key Concepts: P-value interpretation, Cohen's
effect size, Central Limit Theorem (CLT), and t-distributions.
STT 231 Exam 1
Quiz_________________?
1
, What makes up a data set? -
Answer
Data are made up of observational units (cases)
Quiz_________________?
Variable -
Answer
any characteristic or value recorded for each case; found in columns (vertical)
Quiz_________________?
Observations/Observational Units/Cases -
Answer
Found in rows (horizontal)
Quiz_________________?
Values -
Answer
Items that populate a data set
Quiz_________________?
All variables are either ______ or ______ -
2
, Answer
Categorical or numerical
Quiz_________________?
Categorical Variables -
Answer
Identify a case as a measure of a group, placing each case into exactly one of two
or more groups called levels.
Ex. An MSU student can be classified by their year (first second third...) where
these categories are called levels.
Quiz_________________?
Numerical Variables -
Answer
Measure a numerical quantity for each case. Unlike categorical variables,
numerical operations like adding and averaging make sense for these quantitative
variables.
Ex. we can record how many credits an MSU student has earned (1,2,3...)
Quiz_________________?
Numerical Variables can be divided into two groups: ____ and____ -
3
, Answer
Discrete and continuous
Quiz_________________?
Numerical discrete variables -
Answer
can only take on limited values in a variables domain.
Ex. How many siblings do I have? (1,2,3...) but could not say 1.7 siblings.
Quiz_________________?
Numerical Continuous Variables -
Answer
can take on any value in a variable's domain.
Ex. Height-- could be 52in or 53in or 53.262 in
Quiz_________________?
Categorical variables can be divided into 2 groups: ____ and ____ -
Answer
nominal and ordinal
4
