Question 1

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

Accepted Answer

Descriptive statistics summarize and organize data; inferential statistics use sample data to make generalizations about a population.

Question 2

A researcher wants to estimate the average GPA of all students at a university. She randomly selects 200 students and calculates their mean GPA. What is the sample in this study?

Accepted Answer

The 200 randomly selected students

Question 3

Which of the following is an example of a voluntary response sample?

Accepted Answer

A survey posted online where anyone can choose to respond.

Question 4

A study finds that the mean IQ of a sample of 100 students increased by 5 points after a new teaching method was introduced, with a 1% likelihood that this result is due to chance. What does this indicate?

Accepted Answer

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

Question 5

Which of the following variables is qualitative (categorical)?

Accepted Answer

Type of college major (e.g., Biology, Engineering, History)

Question 6

A researcher divides a population into non-overlapping groups based on age, then randomly selects individuals from each group. What sampling method is being used?

Accepted Answer

Stratified random sampling

Question 7

Which of the following is a parameter?

Accepted Answer

The mean GPA of all students at a university

Question 8

A survey of 1,000 Florida residents finds that 28.6% of them are college graduates. What is the population in this study?

Accepted Answer

All Florida residents

Question 9

Which of the following best describes an observational study?

Accepted Answer

The researcher observes and records data without influencing the subjects.

Question 10

A researcher wants to study the effect of a new drug. She randomly assigns patients to receive either the drug or a placebo and compares outcomes. What type of study is this?

Accepted Answer

Experimental study

Question 11

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

Accepted Answer

Type of fruit (apple, banana, orange)

Question 12

A researcher selects every 10th person from a list of 1,000 names. What sampling method is this?

Accepted Answer

Systematic random sampling

Question 13

Which of the following is a discrete variable?

Accepted Answer

Number of children in a family

Question 14

A study finds that 55% of all murders are alcohol related. Is this a statistic or a parameter?

Accepted Answer

Parameter

Question 15

Which of the following is an example of a confounding variable in an experiment?

Accepted Answer

A variable that affects the outcome but is not controlled or measured.

Question 16

A researcher wants to estimate the average salary of employees at a company. She randomly selects 50 employees from each department. What sampling method is this?

Accepted Answer

Stratified random sampling

Question 17

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

Accepted Answer

Height in meters

Question 18

A researcher wants to study the effect of exercise on weight loss. She assigns 100 participants to either an exercise group or a control group and measures their weight after 6 months. What is the treatment group in this study?

Accepted Answer

The group that exercises

Question 19

Which of the following best describes practical significance?

Accepted Answer

A result that is both statistically significant and has real-world importance.

Question 20

A researcher wants to study the relationship between smoking and lung cancer. She uses medical records from hospitals to collect data. What type of study is this?

Accepted Answer

Observational study

Review of Basic Definitions and Terminology in Statistics

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