Business Statistics 2026 TP. Hồ Chí Minh UEH University

Chapter 2–3 Exam: Sampling, Data, and Graphical Analysis

20 questions

150 min

Answer key

Exam info

Subject: Business Statistics
Exam type: University
Questions: 20
Duration: 150 min
Year: 2026
Answers: ✓ With explanations
School: Đại học Kinh tế TP.HCM (UEH)

Questions (20)

Q 1.
A market-research company interviews shoppers who happen to enter a store near its headquarters. What is the primary sampling method?
- A.
  Systematic sampling
- B.
  Convenience sampling
- C.
  Stratified sampling
- D.
  Cluster sampling
Q 2.
Which feature distinguishes convenience and judgment sampling from probability sampling?
- A.
  It guarantees every population member an equal chance of selection.
- B.
  It eliminates selection bias when the sample is large.
- C.
  It does not give population members known, nonzero selection probabilities.
- D.
  It may only be used when a complete sampling frame exists.
Q 3.
Starting with a numbered mailing list, a researcher selects every tenth name. Which sampling method was used?
- A.
  Simple random sampling
- B.
  Cluster sampling
- C.
  Systematic sampling
- D.
  Stratified sampling
Q 4.
A retailer divides its stores into four geographic regions, randomly selects five stores within every region, and records customer satisfaction at each selected store. What is the sampling method?
- A.
  Census
- B.
  Stratified random sampling
- C.
  Cluster random sampling
- D.
  Systematic random sampling
Q 5.
Which item is the best example of a sampling frame for a survey of city residents?
- A.
  A conceptual description of all city residents
- B.
  A numbered list of city residents compiled for the study
- C.
  The city's average income calculated from a previous survey
- D.
  The sample size planned for the study
Q 6.
A researcher calculates a sample mean of 120 dollars. Which statement correctly classifies this value?
- A.
  It is a parameter because it is numerical.
- B.
  It is a statistic because it is calculated from sample observations.
- C.
  It is a parameter because it is intended to describe a population.
- D.
  It cannot be classified without knowing the population size.
Q 7.
Which variable is measured at the nominal level?
- A.
  Credit-card issuer, such as Visa, Mastercard, or American Express
- B.
  Customer satisfaction ranked from very dissatisfied to very satisfied
- C.
  Weight of a package measured in kilograms
- D.
  Number of purchases made during a week
Q 8.
Which measurement has ratio level because its zero is meaningful and ratios are interpretable?
- A.
  Blood type
- B.
  Class rank from freshman through senior
- C.
  Temperature measured in degrees Celsius
- D.
  Elapsed time required to complete a task
Q 9.
Which of the following is a discrete numerical variable?
- A.
  Outside temperature in degrees Celsius
- B.
  Time required to complete a task
- C.
  Number of items purchased
- D.
  Speed of a vehicle
Q 10.
Using a sample to estimate the average waiting time for all customers of a bank is an example of what?
- A.
  Descriptive statistics
- B.
  Inferential statistics
- C.
  Data mining
- D.
  Experimental design
Q 11.
When studying a population of one million households, what is generally true when comparing a census with a sample?
- A.
  A sample is usually more practical and can still provide useful population estimates.
- B.
  A census is always less accurate because of processing errors.
- C.
  A sample must contain at least half of the population to be accurate.
- D.
  Using a sample automatically removes nonresponse bias.
Q 12.
A quality manager orders defect categories by frequency and adds a cumulative-percentage line to identify the small number of causes responsible for most defects. Which chart is being used?
- A.
  Line chart
- B.
  Pareto chart
- C.
  Scatter plot
- D.
  Histogram
Q 13.
Using Sturges’ Rule, , how many classes are recommended for a data set containing 50 observations?
- A.
  6 classes
- B.
  7 classes
- C.
  8 classes
- D.
  9 classes
Q 14.
A frequency distribution contains 1,000 observations, and one class has a relative frequency of 0.12. Which statement correctly identifies the term for the class width and calculates the class frequency?
- A.
  The width is the midpoint, and the class frequency is 120.
- B.
  The width is the class limit, and the class frequency is 120.
- C.
  The width is the class interval, and the class frequency is 120.
- D.
  The width is the class frequency, and the class frequency is 0.12.
Q 15.
Which statement correctly describes a frequency histogram?
- A.
  It uses separated bars to represent individual categorical values.
- B.
  Its bar widths represent class intervals, and its bar areas represent frequencies.
- C.
  Its bar heights always show cumulative frequencies.
- D.
  Its bar widths are arbitrary and do not indicate class intervals.
Q 16.
Which dataset is most appropriately displayed with a line chart?
- A.
  Monthly sales for 24 consecutive months
- B.
  A one-time breakdown of sales by product category
- C.
  The distribution of individual transaction times
- D.
  Paired measurements of advertising expenditure and sales
Q 17.
Which feature cannot be determined directly from a scatter plot?
- A.
  Whether the relationship is nonlinear
- B.
  Whether unusual observations are present
- C.
  Whether observations form separate clusters
- D.
  Which values are missing because of nonresponse
Q 18.
What is the primary purpose of a pivot table?
- A.
  To display cross-tabulations of data
- B.
  To emphasize trends over time
- C.
  To display the frequency distribution of one variable
- D.
  To display the median and quartiles of numerical data
Q 19.
Why might an analyst use a logarithmic vertical scale for two time series that differ greatly in magnitude?
- A.
  It permits comparison of proportional growth in series with very different magnitudes.
- B.
  It makes equal vertical distances represent equal dollar amounts.
- C.
  It converts categorical observations into numerical measurements.
- D.
  It eliminates observations with missing values.
Q 20.
Which practice is identified as a major graphical deception?
- A.
  Failing to identify or clearly state the source of the displayed data
- B.
  Using more than one color or font
- C.
  Making bar widths proportional to bar heights
- D.
  Using a dramatic but factually accurate title

Answers and explanations are in mode.