Question 1

Which of the following best describes the difference between a population and a sample in statistics?

Accepted Answer

A population is the entire group to be studied, while a sample is a subset of that group.

Question 2

A researcher wants to estimate the average income of all residents in a city. She randomly selects 200 residents and records their incomes. In this context, what is the 'statistic'?

Accepted Answer

The average income calculated from the 200 selected residents.

Question 3

Which of the following is an example of a discrete quantitative variable?

Accepted Answer

The number of cars sold at a dealership in a day.

Question 4

A survey asks respondents to indicate their class rank as freshman, sophomore, junior, or senior. What is the level of measurement for this variable?

Accepted Answer

Ordinal

Question 5

Which of the following best describes a simple random sample (SRS)?

Accepted Answer

A sample where every possible sample of a given size has an equal chance of being selected.

Question 6

A researcher divides a population of students into males and females, then randomly selects 50 students from each group. What type of sampling is this?

Accepted Answer

Stratified sampling

Question 7

Which of the following is an example of a variable measured at the ratio level?

Accepted Answer

Income in dollars

Question 8

A study collects data on the favorite color of each student in a school. What type of variable is 'favorite color'?

Accepted Answer

Qualitative (categorical)

Question 9

A medical researcher wants to test the effectiveness of a new drug. She randomly assigns patients to either receive the drug or a placebo and compares their recovery rates. What type of study is this?

Accepted Answer

Designed experiment

Question 10

Which of the following statements about sampling bias is correct?

Accepted Answer

Sampling bias occurs when the sampling method favors one part of the population over another.

Question 11

Suppose a researcher selects every 10th person entering a hospital to participate in a study. What type of sampling method is being used?

Accepted Answer

Systematic sampling

Question 12

Which of the following is a potential source of nonresponse bias in a survey?

Accepted Answer

Some individuals selected for the survey do not respond.

Question 13

A researcher wants to estimate the average test score of all students in a university. She randomly selects 10 classes and includes all students in those classes in her sample. What sampling method is this?

Accepted Answer

Cluster sampling

Question 14

Which of the following is an example of response bias?

Accepted Answer

Respondents give answers they think are socially acceptable rather than their true feelings.

Question 15

Which formula would you use to calculate the number of possible simple random samples of size $$n$$ from a population of size $$N$$?

Accepted Answer

$$\frac{N!}{n!(N-n)!}$$

Question 16

A researcher is interested in the effect of air pollution on lung function. She collects data from existing medical records without influencing the patients. What type of study is this?

Accepted Answer

Observational study

Question 17

Which of the following is NOT a characteristic of data measured at the interval level?

Accepted Answer

A value of zero means the absence of the quantity.

Question 18

A teacher wants to know the average height of students in her school. She stands at the entrance and records the height of the first 50 students who arrive. What type of sampling is this, and what is a likely problem with it?

Accepted Answer

Convenience sampling; likely to be biased

Question 19

Which of the following best describes inferential statistics?

Accepted Answer

Extending results from a sample to the population and measuring the reliability of the result.

Question 20

A study measures the air temperature in degrees Kelvin. What is the level of measurement for this variable?

Accepted Answer

Ratio

Chapter 1: Data Collection in Statistics

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