COLLEGE 2026 COMPLETE REVIEW
QUESTIONS AND ANSWERS VERIFIED GRADED
A+
◉ Variable. Answer: A particular characteristic measured or
recorded about an individual.
◉ Quantitative Variable. Answer: Measures something using a
standard unit (length, weight, time, temperature, etc.).
◉ Continuous Quantitative Variable. Answer: Has infinite possible
values between any two values; involves decimals.
◉ Discrete Quantitative Variable. Answer: Whole-number counts
(e.g., number of students, number of pets).
◉ Categorical Variable. Answer: Identifies groups or categories
(ethnicity, class year, country, etc.).
◉ Levels of Measurement: Ratio. Answer: Zero means total absence;
supports +, -, ×, ÷ (e.g., weight, height, Kelvin temperature).
, ◉ Levels of Measurement: Interval. Answer: Zero is a placeholder;
supports + and - only (e.g., IQ, pH, °C, °F).
◉ Levels of Measurement: Nominal. Answer: Named categories with
no order (sex, ethnicity, disease type).
◉ Levels of Measurement: Ordinal. Answer: Categories with a
meaningful order (small/medium/large, 1st/2nd/3rd).
◉ Quantitative Variables in R. Answer: Stored as integer, double, or
numeric.
◉ Categorical Variables in R. Answer: Stored as factors with levels.
◉ Other R Types. Answer: Character = text; logical = TRUE/FALSE.
◉ Confounder. Answer: An unmeasured variable that falsely
suggests correlation or causation between other variables.
◉ Controlling Confounders: Standardization. Answer: Measure
confounders and mathematically adjust to remove their influence.
◉ Controlling Confounders: Randomization. Answer: Randomly
assign subjects to groups to balance confounders.