MATH 1280 (Introduction to Statistics)
, updated for the 2026/2027 syllabus.
It contains over 100 questions covering key concepts: R
Programming, Descriptive Statistics, Probability, Random
Variables, The Normal Distribution, Sampling, and
Inference.
Unit 1: Introduction to Statistics & R
1. What is the difference between a population and a sample?
ANSWER ✓ A population is the entire group of interest, while a sample is a subset of
the population used to collect data.
2. In the R command x <- c(2, 4, 6), what does the c() function do?
ANSWER ✓ It "combines" values into a vector.
3. How do you find the mean of a vector named data in R?
ANSWER ✓ mean(data)
4. What is the purpose of the read.csv() function in R?
ANSWER ✓ It reads data from a Comma Separated Values (CSV) file into a data frame.
5. If you receive a warning "package ‘ggplot2’ is not available," what R function
must you run first?
ANSWER ✓ install.packages("ggplot2")
6. What does the summary() function in R return?
ANSWER ✓ For numeric data, it returns the minimum, 1st quartile, median, mean, 3rd
quartile, and maximum.
7. What symbol is used to assign a value to a variable in R (the standard
assignment operator)?
ANSWER ✓ <-
, 8. A study measures the blood pressure of every person in a specific city. Is this a
parameter or a statistic?
ANSWER ✓ Parameter (because it involves the entire population of the city).
9. What is the difference between descriptive and inferential statistics?
ANSWER ✓ Descriptive statistics summarizes data (e.g., mean, graphs). Inferential
statistics uses sample data to make predictions or inferences about a population.
10. What is the purpose of the library() command after installing a package?
ANSWER ✓ It loads the package into the current R session so its functions can be used.
Unit 2: Sampling & Data Structures
11. What type of sampling method involves dividing the population into groups
and then randomly selecting entire groups to survey?
ANSWER ✓ Cluster Sampling.
12. You assign every person in a population a number and use a random number
generator to pick participants. What is this sampling method?
ANSWER ✓ Simple Random Sampling (SRS).
13. If a survey asks "How many hours do you sleep?" what type of data is this
(quantitative or qualitative)?
ANSWER ✓ Quantitative (numerical).
14. If a survey asks "What is your favorite color?" what type of data is this?
ANSWER ✓ Qualitative (categorical).
15. In R, how would you access the third element of a vector named results?
ANSWER ✓ results[3]
16. What is a confounding variable?
ANSWER ✓ A variable that influences both the dependent variable and independent
variable, causing a spurious association.
17. What is the difference between an observational study and an experiment?
ANSWER ✓ In an experiment, the researcher imposes a treatment; in an observational
study, the researcher merely observes without interference.
, updated for the 2026/2027 syllabus.
It contains over 100 questions covering key concepts: R
Programming, Descriptive Statistics, Probability, Random
Variables, The Normal Distribution, Sampling, and
Inference.
Unit 1: Introduction to Statistics & R
1. What is the difference between a population and a sample?
ANSWER ✓ A population is the entire group of interest, while a sample is a subset of
the population used to collect data.
2. In the R command x <- c(2, 4, 6), what does the c() function do?
ANSWER ✓ It "combines" values into a vector.
3. How do you find the mean of a vector named data in R?
ANSWER ✓ mean(data)
4. What is the purpose of the read.csv() function in R?
ANSWER ✓ It reads data from a Comma Separated Values (CSV) file into a data frame.
5. If you receive a warning "package ‘ggplot2’ is not available," what R function
must you run first?
ANSWER ✓ install.packages("ggplot2")
6. What does the summary() function in R return?
ANSWER ✓ For numeric data, it returns the minimum, 1st quartile, median, mean, 3rd
quartile, and maximum.
7. What symbol is used to assign a value to a variable in R (the standard
assignment operator)?
ANSWER ✓ <-
, 8. A study measures the blood pressure of every person in a specific city. Is this a
parameter or a statistic?
ANSWER ✓ Parameter (because it involves the entire population of the city).
9. What is the difference between descriptive and inferential statistics?
ANSWER ✓ Descriptive statistics summarizes data (e.g., mean, graphs). Inferential
statistics uses sample data to make predictions or inferences about a population.
10. What is the purpose of the library() command after installing a package?
ANSWER ✓ It loads the package into the current R session so its functions can be used.
Unit 2: Sampling & Data Structures
11. What type of sampling method involves dividing the population into groups
and then randomly selecting entire groups to survey?
ANSWER ✓ Cluster Sampling.
12. You assign every person in a population a number and use a random number
generator to pick participants. What is this sampling method?
ANSWER ✓ Simple Random Sampling (SRS).
13. If a survey asks "How many hours do you sleep?" what type of data is this
(quantitative or qualitative)?
ANSWER ✓ Quantitative (numerical).
14. If a survey asks "What is your favorite color?" what type of data is this?
ANSWER ✓ Qualitative (categorical).
15. In R, how would you access the third element of a vector named results?
ANSWER ✓ results[3]
16. What is a confounding variable?
ANSWER ✓ A variable that influences both the dependent variable and independent
variable, causing a spurious association.
17. What is the difference between an observational study and an experiment?
ANSWER ✓ In an experiment, the researcher imposes a treatment; in an observational
study, the researcher merely observes without interference.
