Question 1

Which of the following best describes the main goal of statistics?

Accepted Answer

To use data to make informed decisions and draw conclusions about populations.

Question 2

A researcher wants to estimate the average height of all university students. She measures the height of 200 randomly selected students. In this scenario, which term best describes the group of all university students?

Accepted Answer

Population

Question 3

Which of the following is an example of a parameter?

Accepted Answer

The average age of all residents in a city.

Question 4

Which of the following best distinguishes descriptive statistics from inferential statistics?

Accepted Answer

Descriptive statistics summarize data, while inferential statistics draw conclusions about populations based on samples.

Question 5

A survey is conducted by sending questionnaires to 1,000 randomly selected households, but only 400 respond. Which type of bias is most likely present?

Accepted Answer

Nonresponse bias

Question 6

Which sampling method involves dividing the population into groups and then randomly selecting entire groups to participate?

Accepted Answer

Cluster sampling

Question 7

A medical study assigns patients to receive either a new drug or a placebo without knowing which they receive, and the researchers also do not know which treatment each patient receives. What type of study is this?

Accepted Answer

Double blind study

Question 8

Which of the following is a potential pitfall in statistical analysis that can lead to misleading results?

Accepted Answer

Collecting data using convenience sampling

Question 9

In an experiment studying the effect of fertilizer on plant growth, what is the response variable?

Accepted Answer

The growth of the plant measured in centimeters

Question 10

Which of the following best describes a randomized block design (RBD)?

Accepted Answer

Subjects are grouped based on a characteristic, and then randomly assigned to treatments within each group.

Question 11

A researcher uses systematic sampling to select every 10th person from a list of 1,000 names. Which formula would best describe the probability of any one person being selected?

Accepted Answer

$$P = \frac{1}{10}$$

Question 12

Which of the following is an example of a nonsampling error?

Accepted Answer

Recording incorrect data due to a faulty measuring instrument.

Question 13

A study collects data on the number of hours students study per week. Which level of measurement is this data?

Accepted Answer

Ratio

Question 14

Which of the following best describes a convenience sample?

Accepted Answer

A sample selected based on ease of access to participants.

Question 15

In a clinical trial, what is the purpose of replication?

Accepted Answer

To increase the reliability of results by repeating the experiment with multiple subjects.

Question 16

Which of the following is a key difference between an observational study and an experimental study?

Accepted Answer

Experimental studies assign treatments to subjects, while observational studies do not.

Question 17

A researcher divides a population into male and female groups, then randomly selects equal numbers from each group. Which sampling method is this?

Accepted Answer

Stratified sampling

Question 18

Which of the following is most likely to cause undercoverage bias?

Accepted Answer

Using a sample that excludes certain segments of the population.

Question 19

In a study, the explanatory variable is best defined as:

Accepted Answer

The variable that is manipulated to observe its effect on the response variable.

Question 20

A researcher wants to study the effect of a new teaching method. She randomly assigns students to two groups: one receives the new method, the other receives the traditional method. What is the experimental unit in this study?

Accepted Answer

Each individual student

Introductory Statistics: Data Collection, Sampling, and Study Design

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