Chapter 1 Homework — Multiple Choice
Sampling and Data — 20 multiple-choice questions covering definitions, sampling techniques, sources of bias, and frequency tables.
Choose the single best answer for each question.
1.1 — Definitions, Population vs Sample, Parameter vs Statistic
- 1.
Which of the following best describes "statistics" as a discipline?
- A.The study of probability theory only
- B.The science of planning studies and experiments, obtaining data, and then organizing, summarizing, analyzing, and drawing conclusions from the data
- C.The collection of numerical facts about a population
- D.The use of mathematical equations to predict the future
- 2.
A sample is best defined as:
- A.The entire group being studied
- B.A subset of the population that is being studied
- C.A numerical summary of the population
- D.Every person who answers a survey
- 3.
The mean weight of all 4,200 students at a university is reported as 158 pounds. The value 158 pounds is best described as:
- A.A statistic
- B.A parameter
- C.A variable
- D.An individual
- 4.
A poll of 800 randomly selected adults found that 62% support a new tax law. The 62% is best described as:
- A.A parameter
- B.A statistic
- C.The population
- D.An individual
- 5.
Which of the following is an example of descriptive (rather than inferential) statistics?
- A.Predicting the outcome of a national election from a sample of 1,500 voters
- B.Reporting the average height of the 25 students in a particular classroom
- C.Estimating the proportion of defective parts in a shipment based on a small sample
- D.Using a sample mean to estimate the population mean
1.2 — Types of Data
- 6.
Which variable is qualitative (categorical)?
- A.Age in years
- B.Number of cars sold last week
- C.Eye color
- D.Length of a phone call in minutes
- 7.
Which variable is quantitative?
- A.Favorite movie genre
- B.ZIP code
- C.Number of pets owned
- D.Brand of phone
- 8.
Which variable is discrete?
- A.Volume of water in a swimming pool
- B.Time to run a marathon
- C.Number of goals scored in a soccer game
- D.Outdoor temperature at noon
- 9.
Which variable is continuous?
- A.Number of books on a shelf
- B.Height of a person, in centimeters
- C.Number of students enrolled in a class
- D.Number of text messages sent today
1.2 — Sampling Techniques
- 10.
A researcher numbers all 500 employees of a company and uses a random number generator to choose 30 of them to interview. This is an example of:
- A.Convenience sampling
- B.Stratified sampling
- C.Cluster sampling
- D.Simple random sampling
- 11.
A factory inspects every 20th item that comes off the assembly line. This is an example of:
- A.Systematic sampling
- B.Cluster sampling
- C.Simple random sampling
- D.Convenience sampling
- 12.
A school has 600 freshmen, 500 sophomores, 400 juniors, and 300 seniors. To survey students, an administrator randomly selects 30 students from each class level. This is an example of:
- A.Cluster sampling
- B.Stratified sampling
- C.Simple random sampling
- D.Systematic sampling
- 13.
A school district has 80 elementary schools. To estimate average reading scores, a researcher randomly chooses 5 schools and tests every student in those 5 schools. This is an example of:
- A.Stratified sampling
- B.Systematic sampling
- C.Cluster sampling
- D.Convenience sampling
- 14.
A reporter interviews the first 25 people who walk past a downtown bus stop. The most accurate description of this method is:
- A.Simple random sampling
- B.Stratified sampling
- C.Convenience sampling
- D.Systematic sampling
1.2 — Sources of Bias
- 15.
A magazine publishes a survey on its website and uses only the responses of readers who choose to fill it out. About 4% of subscribers respond. The most likely source of bias is:
- A.There is no bias because the survey reached every subscriber
- B.Nonresponse bias
- C.Response bias
- D.Sampling error only
- 16.
A radio talk show asks listeners to call in and vote on a proposed local ordinance. The audience is mostly retirees who listen during the day. This is an example of:
- A.Sampling bias
- B.Nonresponse bias
- C.Response bias
- D.Random sampling
- 17.
In a face-to-face interview, subjects are asked how often they cheat on their taxes. The most likely source of bias is:
- A.Sampling bias
- B.Nonresponse bias
- C.Response bias
- D.Random error
1.3 — Frequency, Relative Frequency, and Cumulative Frequency
- 18.
Which best defines relative frequency?
- A.The number of observations in a category
- B.The proportion of observations in a category relative to the total number of observations
- C.The cumulative total of all categories
- D.The midpoint of a class interval
- 19.
Eighty students take an exam, and 12 of them earn a B. The relative frequency of "B" is:
- A.12
- B.0.12
- C.0.15
- D.0.20
- 20.
In a frequency distribution, the cumulative frequency of a class is best described as:
- A.The frequency of that class divided by the total
- B.The frequency of that class minus the frequency of the previous class
- C.The sum of the frequencies of that class and all previous classes
- D.The total number of classes in the distribution
- 21.
A relative frequency distribution is correctly constructed if the relative frequencies:
- A.Sum to the total number of observations
- B.Sum to 1 (or about 1, due to rounding)
- C.Are all equal
- D.Sum to 100