Question 1

Which of the following best describes a simple random sample?

Accepted Answer

A sample in which every possible sample of the same size n has the same chance of being chosen.

Question 2

A pharmaceutical company wants to test a new drug. They randomly assign patients to receive either the drug or a placebo, and neither the patients nor the researchers know who receives which. What type of experimental design is this?

Accepted Answer

Double-blind experiment

Question 3

Which sampling method is illustrated by selecting every 5th car that passes a checkpoint?

Accepted Answer

Systematic sampling

Question 4

A researcher divides a city into neighborhoods, randomly selects three neighborhoods, and surveys every household in those neighborhoods. What sampling method is this?

Accepted Answer

Cluster sampling

Question 5

Which of the following is an example of a lurking variable?

Accepted Answer

A variable that affects the variables being studied but is not included in the analysis.

Question 6

In a study, researchers observe the eating habits of participants without intervening. What type of study is this?

Accepted Answer

Observational study

Question 7

Which of the following best describes a retrospective study?

Accepted Answer

Data are collected from a past time period by going back in time.

Question 8

A researcher wants to compare the effectiveness of two diets. She matches participants in pairs based on age and gender, then randomly assigns one from each pair to each diet. What design is this?

Accepted Answer

Matched pairs design

Question 9

Which of the following is a potential source of nonsampling error?

Accepted Answer

Entering data incorrectly during analysis

Question 10

A pollster divides the population into men and women, then randomly selects 50 men and 50 women to survey. What sampling method is this?

Accepted Answer

Stratified sampling

Question 11

Which of the following best describes confounding in an experiment?

Accepted Answer

When the effect of two or more variables cannot be distinguished from each other

Question 12

A researcher uses a combination of stratified and cluster sampling in different stages of a survey. What is this method called?

Accepted Answer

Multistage sampling

Question 13

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

Accepted Answer

A discrepancy between a sample result and the true population result due to chance fluctuations

Question 14

A researcher selects a sample of college students by standing outside the library and surveying the first 20 students who walk by. What type of sampling is this?

Accepted Answer

Convenience sampling

Question 15

Which of the following is a key advantage of randomization in experimental design?

Accepted Answer

It uses chance to create groups that are similar, reducing bias.

Question 16

In a clinical trial, some patients report improvement after receiving a sugar pill. What is this phenomenon called?

Accepted Answer

Placebo effect

Question 17

Which of the following best describes a prospective study?

Accepted Answer

Data are collected in the future from groups sharing common factors.

Question 18

A researcher wants to ensure that the effects of a new teaching method are not confounded by students' prior math ability. She forms groups of students with similar math backgrounds and randomly assigns the teaching method within each group. What design is this?

Accepted Answer

Randomized block design

Question 19

Which of the following is NOT a characteristic of a well-designed experiment?

Accepted Answer

Convenience sampling

Question 20

A researcher collects data on smoking habits and lung cancer rates by reviewing medical records from the past 20 years. What type of study is this?

Accepted Answer

Retrospective study

Chapter 1: Introduction to Statistics – Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards