Question 1

Which of the following best describes a discrete variable?

Accepted Answer

A variable that can only take specific, separate values, such as whole numbers.

Question 2

A pharmaceutical company is testing a new drug. To ensure unbiased results, neither the participants nor the researchers know who receives the drug or the placebo. What is this experimental design called?

Accepted Answer

Double blind experiment

Question 3

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

Accepted Answer

The color of shirts worn by students

Question 4

A researcher wants to study the eating habits of all university students but only surveys 200 randomly selected students. What is the group of 200 students called?

Accepted Answer

Sample

Question 5

Which equation correctly represents the probability of selecting a random individual from a population of $$N$$ individuals?

Accepted Answer

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

Question 6

A study finds that a new teaching method improves test scores by 0.5 points on average, with a $$p-$$value of $$0.01. $$Which statement best describes the result?

Accepted Answer

The result is statistically significant but may not be practically significant.

Question 7

Which sampling method is most likely to introduce bias?

Accepted Answer

Convenience sampling

Question 8

In a medical trial, a placebo is used to:

Accepted Answer

Control for psychological effects unrelated to the treatment.

Question 9

Which of the following best defines a census?

Accepted Answer

A survey of all members of a population.

Question 10

A variable measuring the time (in seconds) it takes for a chemical reaction to complete is:

Accepted Answer

Continuous and quantitative

Question 11

Which of the following is NOT a characteristic of a double blind experiment?

Accepted Answer

Only participants are unaware of their group assignment.

Question 12

A researcher uses convenience sampling to survey students leaving the library. Which is a likely consequence?

Accepted Answer

The sample may be biased toward students who use the library.

Question 13

Which of the following best describes practical significance?

Accepted Answer

A result that has real-world importance or impact.

Question 14

A variable representing the number of accidents at an intersection each month is:

Accepted Answer

Discrete and quantitative

Question 15

Which of the following is an example of blinding in an experiment?

Accepted Answer

Participants do not know whether they receive the treatment or placebo.

Question 16

A sample is best defined as:

Accepted Answer

A subset of the population selected for study.

Question 17

Which of the following is a quantitative variable?

Accepted Answer

Number of books read in a year

Question 18

A researcher wants to estimate the average height of all adults in a city. She measures the height of 1,000 randomly selected adults. What is the population in this study?

Accepted Answer

All adults in the city

Question 19

Which of the following statements about statistical significance is correct?

Accepted Answer

Statistical significance means the result is unlikely to have occurred by chance.

Question 20

A researcher randomly selects 50 patients from a hospital to study their recovery times. Which sampling method is used?

Accepted Answer

Random sampling

Introductory Statistics Study Guide: Key Concepts and Practice

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