Exam 2026/2027 – Complete All-Module Test Bank with
Detailed Rationales | 100% Verified | Pass Guaranteed – A+
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Section A: Module 1 Exam – Introduction to Statistics & Data Types
Q1: A researcher computes the average exam score of 50 randomly selected Portage
Learning students and obtains 82.4. This numerical summary, which describes a
characteristic of a sample, is called a:
A. Parameter
B. Statistic [CORRECT]
C. Population
D. Census
Correct Answer: B
Rationale: A statistic is a numerical measurement describing a sample characteristic,
while a parameter describes a population. A census collects data from the entire
population, so 82.4 from 50 sampled students is a statistic.
Q2: A survey asks college students how many textbooks they purchased this semester,
recording answers such as 0, 1, 2, or 3. The variable "number of textbooks purchased" is
best classified as:
A. Nominal
B. Continuous quantitative
C. Discrete quantitative [CORRECT]
D. Ordinal
Correct Answer: C
Rationale: The variable is numerical and countable (finite, whole-number values),
making it discrete quantitative. Continuous data can take infinitely many values within
an interval, and nominal/ordinal describe qualitative categories.
Q3: To assess student satisfaction, a college divides students into freshmen,
sophomores, juniors, and seniors, then randomly selects 25 students from each group.
This sampling method is:
,A. Stratified sampling [CORRECT]
B. Convenience sampling
C. Cluster sampling
D. Simple random sampling
Correct Answer: A
Rationale: In stratified sampling, the population is divided into subgroups (strata) and
random samples are drawn from EACH group. Cluster sampling selects entire groups,
and convenience sampling uses easily accessed subjects.
Q4: Data at the nominal level of measurement are characterized by:
A. Categories that can be ranked in a meaningful order
B. Equal intervals between consecutive values
C. A true (absolute) zero point
D. Categories with names or labels only, with no natural order [CORRECT]
Correct Answer: D
Rationale: Nominal data consist of names, labels, or categories with no natural ranking
(e.g., blood type, eye color). Ordering requires ordinal level, equal intervals require
interval level, and a true zero defines the ratio level.
Q5: Researchers randomly assign 200 smokers to either a nicotine patch group or a
placebo group and compare quit rates after 6 months. This study is best classified as:
A. An observational study
B. An experiment [CORRECT]
C. A case-control study
D. A census
Correct Answer: B
Rationale: Random assignment of subjects to treatment groups is the defining feature
of an experiment, allowing cause-and-effect conclusions. Observational studies
(including case-control) only observe without assigning treatments.
Q6: A health district randomly selects 5 of its 40 clinics and then surveys EVERY patient
at those 5 clinics. This sampling method is:
A. Stratified sampling
B. Systematic sampling
C. Cluster sampling [CORRECT]
D. Simple random sampling
, Correct Answer: C
Rationale: Cluster sampling divides the population into groups (clusters) and randomly
selects entire clusters — all individuals within chosen clusters are sampled. Stratified
sampling samples individuals from every group instead.
Q7: Which of the following is an example of a continuous quantitative variable?
A. The height of a student, measured as 165.37 cm [CORRECT]
B. The number of cars in a parking lot
C. The number of children in a family
D. A student's letter grade (A, B, C)
Correct Answer: A
Rationale: Height can take any value within a range (including decimals) and is
measurable, making it continuous. Countable quantities like numbers of cars or children
are discrete, and letter grades are qualitative.
Q8: A mall interviewer surveys shoppers who voluntarily walk up to the booth during one
afternoon. The main flaw in this sampling approach is:
A. Random sampling error
B. Undercoverage of the entire population of interest
C. Use of a stratified design
D. Convenience (voluntary response) sampling, which introduces bias [CORRECT]
Correct Answer: D
Rationale: Surveying whoever is easily available and willing creates
convenience/voluntary response bias — the sample is unlikely to represent the
population. It is not a probability design, so results cannot be generalized reliably.
Q9: In statistical notation, the symbol μ (mu) represents:
A. The sample mean
B. The population mean [CORRECT]
C. The sample standard deviation
D. The population proportion
Correct Answer: B
Rationale: μ denotes the population mean, while x̄ denotes the sample mean. The
population proportion is p, and the population standard deviation is σ.