STAT 201 QUIZ QUESTIONS ANSWERED CORRECTLY LATEST UPDATE 2026
Statistics - AnswersThe study of how to collect, analyze, interpret, present, and draw conclusions from
data
Data - AnswersAny collection of numbers, characters, images, or items that provide information
Population - AnswersThe entire group of interest in a study
Sample - AnswersA subset of the population used to draw conclusions
Individual (Subject) - AnswersA single person or object in the population
Variable - AnswersA characteristic of an individual that can take different values
Qualitative variable - AnswersDescribes qualities or categories (non-numeric)
Quantitative variable - AnswersNumerical variable that measures quantity
Parameter - AnswersA numerical summary of a population (usually unknown)
Statistic - AnswersA numerical summary calculated from a sample
Descriptive statistics - AnswersMethods for organizing, summarizing, and displaying data
Inferential statistics - AnswersMethods for drawing conclusions about a population from a sample
Exploratory Data Analysis (EDA) - AnswersAnother name for descriptive statistics
Census - AnswersAn official count of an entire population
Why use samples instead of a census? - AnswersTime, cost, population size, or destructive testing
Sampling error - AnswersRandom differences between a sample and the population
Bias - AnswersA systematic error in one direction
Sampling frame - AnswersThe list from which a sample is drawn
Representative sample - AnswersA sample that reflects the characteristics of the population
Convenience sample - AnswersSample chosen based on ease of access (biased)
Quota sample - AnswersSample chosen to match subgroup proportions (not random)
Selection bias - AnswersCertain groups are systematically excluded or favored
Response bias - AnswersParticipants give inaccurate or untruthful answers
Non-response bias - AnswersDifferences between those who respond and those who don't
Random sample (probability sample) - AnswersA sample where selection probabilities are known
Sampling with replacement - AnswersIndividuals can be selected more than once
Sampling without replacement - AnswersIndividuals can only be selected once
Simple Random Sample (SRS) - AnswersEvery member has an equal chance of selection
Systematic sampling - AnswersSelect every k-th individual after a random start
Stratified sampling - AnswersDivide population into groups, sample within each group
Cluster sampling - AnswersRandomly select clusters and include all members in them
Key difference: stratified vs cluster - AnswersStratified samples individuals; cluster samples entire
groups
Observational study - AnswersObserve individuals without assigning treatments
Randomized experiment - AnswersRandomly assign subjects to treatments
Response variable - AnswersOutcome being measured
Explanatory variable - AnswersVariable believed to influence the response
Lurking variable - AnswersA variable not studied that may affect results
Cause-and-effect can be proven by - AnswersRandomized experiments only
Subjects (experimental units) - AnswersIndividuals studied in an experiment
Treatment - AnswersA specific condition applied to subjects
Blocking - AnswersGrouping similar subjects to control variability
Control group - AnswersGroup that receives no treatment or a placebo
Placebo - AnswersFake treatment with no active effect
Placebo effect - AnswersImprovement due to belief in treatment
Blinding - AnswersSubjects don't know which treatment they receive
Double-blind experiment - AnswersNeither subjects nor researchers know treatment assignments
Randomized comparative experiment - AnswersUses random assignment and compares treatments
Generalization requires - AnswersA representative sample
Causal conclusions require - AnswersRandom assignment
Right-skewed distribution - AnswersMean > median
Left-skewed distribution - AnswersMean < median
Outliers - AnswersExtreme values far from the rest of the data
IQR - AnswersQ3 − Q1
Statistics - AnswersThe study of how to collect, analyze, interpret, present, and draw conclusions from
data
Data - AnswersAny collection of numbers, characters, images, or items that provide information
Population - AnswersThe entire group of interest in a study
Sample - AnswersA subset of the population used to draw conclusions
Individual (Subject) - AnswersA single person or object in the population
Variable - AnswersA characteristic of an individual that can take different values
Qualitative variable - AnswersDescribes qualities or categories (non-numeric)
Quantitative variable - AnswersNumerical variable that measures quantity
Parameter - AnswersA numerical summary of a population (usually unknown)
Statistic - AnswersA numerical summary calculated from a sample
Descriptive statistics - AnswersMethods for organizing, summarizing, and displaying data
Inferential statistics - AnswersMethods for drawing conclusions about a population from a sample
Exploratory Data Analysis (EDA) - AnswersAnother name for descriptive statistics
Census - AnswersAn official count of an entire population
Why use samples instead of a census? - AnswersTime, cost, population size, or destructive testing
Sampling error - AnswersRandom differences between a sample and the population
Bias - AnswersA systematic error in one direction
Sampling frame - AnswersThe list from which a sample is drawn
Representative sample - AnswersA sample that reflects the characteristics of the population
Convenience sample - AnswersSample chosen based on ease of access (biased)
Quota sample - AnswersSample chosen to match subgroup proportions (not random)
Selection bias - AnswersCertain groups are systematically excluded or favored
Response bias - AnswersParticipants give inaccurate or untruthful answers
Non-response bias - AnswersDifferences between those who respond and those who don't
Random sample (probability sample) - AnswersA sample where selection probabilities are known
Sampling with replacement - AnswersIndividuals can be selected more than once
Sampling without replacement - AnswersIndividuals can only be selected once
Simple Random Sample (SRS) - AnswersEvery member has an equal chance of selection
Systematic sampling - AnswersSelect every k-th individual after a random start
Stratified sampling - AnswersDivide population into groups, sample within each group
Cluster sampling - AnswersRandomly select clusters and include all members in them
Key difference: stratified vs cluster - AnswersStratified samples individuals; cluster samples entire
groups
Observational study - AnswersObserve individuals without assigning treatments
Randomized experiment - AnswersRandomly assign subjects to treatments
Response variable - AnswersOutcome being measured
Explanatory variable - AnswersVariable believed to influence the response
Lurking variable - AnswersA variable not studied that may affect results
Cause-and-effect can be proven by - AnswersRandomized experiments only
Subjects (experimental units) - AnswersIndividuals studied in an experiment
Treatment - AnswersA specific condition applied to subjects
Blocking - AnswersGrouping similar subjects to control variability
Control group - AnswersGroup that receives no treatment or a placebo
Placebo - AnswersFake treatment with no active effect
Placebo effect - AnswersImprovement due to belief in treatment
Blinding - AnswersSubjects don't know which treatment they receive
Double-blind experiment - AnswersNeither subjects nor researchers know treatment assignments
Randomized comparative experiment - AnswersUses random assignment and compares treatments
Generalization requires - AnswersA representative sample
Causal conclusions require - AnswersRandom assignment
Right-skewed distribution - AnswersMean > median
Left-skewed distribution - AnswersMean < median
Outliers - AnswersExtreme values far from the rest of the data
IQR - AnswersQ3 − Q1
