Question 1

Which of the following best describes an observational study?

Accepted Answer

A researcher observes and measures characteristics of interest without influencing the subjects.

Question 2

A pharmaceutical company wants to test a new drug. They divide 200 patients into two groups: one receives the drug, and the other receives a placebo. Neither the patients nor the doctors know who receives the drug. What type of experimental design is this?

Accepted Answer

Double-blind experiment

Question 3

Which of the following is an example of a simulation in statistics?

Accepted Answer

Using a computer model to study the effects of car crashes on passengers

Question 4

A researcher wants to study the effect of a new fertilizer on plant growth. She divides the plants into two groups based on species, then randomly assigns half of each species to receive the fertilizer and the other half to serve as controls. What sampling technique is being used?

Accepted Answer

Stratified sampling

Question 5

Which of the following is a key element of a well-designed experiment?

Accepted Answer

All of the above

Question 6

A coffee shop owner remodels her shop at the same time a new mall opens nearby. Business increases, but she cannot tell if it is due to the remodeling or the mall. What is this an example of?

Accepted Answer

Confounding variable

Question 7

Which of the following best describes a simple random sample?

Accepted Answer

Every possible sample of the same size has the same chance of being selected.

Question 8

A researcher selects every 10th person entering a hospital for a study. What sampling technique is this?

Accepted Answer

Systematic sampling

Question 9

Why is replication important in experimental design?

Accepted Answer

It increases the reliability and validity of the results.

Question 10

A study is conducted to determine whether the primary reason for physicians choosing their career is financial stability. Which data collection method is most appropriate?

Accepted Answer

Survey

Question 11

Which of the following is a potential problem with using a convenience sample?

Accepted Answer

It often leads to biased results.

Question 12

A researcher pairs up subjects according to age and randomly assigns one from each pair to receive a treatment. What experimental design is this?

Accepted Answer

Matched-pairs design

Question 13

Which of the following best describes the placebo effect?

Accepted Answer

Subjects respond favorably to a fake treatment.

Question 14

A company tests a new product by giving it to five people and a placebo to another five. After two months, they conclude the product is effective. What is the main flaw in this experiment?

Accepted Answer

The sample size is too small for valid results.

Question 15

Which of the following is the correct formula for the probability of selecting a specific sample in a simple random sample of size $$n$$ from a population of size $$N$$?

Accepted Answer

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

Question 16

Which of the following scenarios best illustrates a stratified sampling method?

Accepted Answer

Dividing a population into income groups and randomly sampling from each group

Question 17

A sampling error is best defined as:

Accepted Answer

The difference between the results of a sample and those of the population.

Question 18

Which of the following is NOT a recommended method for collecting a representative sample?

Accepted Answer

Convenience sampling

Question 19

In a randomized block design, what is the main purpose of dividing subjects into blocks?

Accepted Answer

To control for variables that might affect the outcome

Question 20

Which of the following best describes a cluster sample?

Accepted Answer

Dividing the population into groups and selecting all members from some groups

Chapter 1: Introduction to Statistics – Data Collection and Experimental Design

Guida di studio - Domande di pratica

Study guide - Flashcard