Question 1

Which of the following best describes the difference between descriptive statistics and inferential statistics?

Accepted Answer

Descriptive statistics summarize and organize data, while inferential statistics draw conclusions or make predictions about a population based on sample data.

Question 2

A researcher wants to study the effect of a new medication on blood pressure. She randomly assigns 100 patients to receive either the medication or a placebo and measures their blood pressure after 6 weeks. What type of study is this?

Accepted Answer

Designed experiment

Question 3

Which of the following is NOT a basic principle of experimental design?

Accepted Answer

Convenience

Question 4

Suppose a school wants to survey students about cafeteria food. They divide students by grade level and randomly select 10 students from each grade. What sampling method is being used?

Accepted Answer

Stratified random sampling

Question 5

Which of the following best defines a population in statistics?

Accepted Answer

All individuals or items of interest in a statistical study

Question 6

A polling organization selects every 10th person from a list of registered voters. What type of sampling method is this?

Accepted Answer

Systematic random sampling

Question 7

Which of the following is an example of bias in sampling?

Accepted Answer

Surveying only people who are at the mall during the afternoon

Question 8

In a designed experiment, what is the primary purpose of randomization?

Accepted Answer

To reduce the effects of confounding variables

Question 9

A researcher collects data on the heights of all students in a university. What type of data collection is this?

Accepted Answer

Census

Question 10

Which formula would you use to calculate the probability of selecting a specific individual from a simple random sample of size $$n$$ from a population of size $$N ($$without replacement)?

Accepted Answer

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

Question 11

A city is divided into 20 neighborhoods. The city council randomly selects 5 neighborhoods and surveys all residents in those neighborhoods. What sampling method is this?

Accepted Answer

Cluster sampling

Question 12

Which of the following best describes a response variable in an experiment?

Accepted Answer

The variable that is measured to assess the effect of treatments

Question 13

A researcher uses a random-number table to select a sample of 50 students from a list of 500. What type of sampling is this?

Accepted Answer

Simple random sampling

Question 14

Which of the following is a key advantage of stratified random sampling over simple random sampling?

Accepted Answer

It ensures that all subgroups of the population are represented

Question 15

In an experiment, what is the main reason for using replication?

Accepted Answer

To reduce the effect of random variation

Question 16

A researcher wants to study the effect of income on health outcomes. She divides the population into income groups and randomly samples from each group. What is the main purpose of this approach?

Accepted Answer

To ensure each income group is represented in the sample

Question 17

Which of the following is an example of convenience sampling?

Accepted Answer

Surveying people who happen to be in a coffee shop

Question 18

If a study collects data on smoking habits and lung health without manipulating any variables, what type of study is this?

Accepted Answer

Observational study

Question 19

Which of the following best describes a sample in statistics?

Accepted Answer

A subset of the population selected for analysis

Question 20

A researcher wants to estimate the average commute time for all workers in a city. She surveys a randomly selected group of 200 workers. Which term best describes the group of 200 workers?

Accepted Answer

Sample

Chapter 1: Data Collection – Foundations of Statistics

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