Question 1

Which of the following best describes the difference between a parameter and a statistic?

Accepted Answer

A parameter is a numerical measurement describing a characteristic of a population, while a statistic describes a characteristic of a sample.

Question 2

A researcher wants to estimate the average cholesterol level of adults in a city. She randomly selects 200 adults from the city and measures their cholesterol levels. What is the population in this study?

Accepted Answer

All adults in the city.

Question 3

Which of the following is an example of a categorical (qualitative) variable?

Accepted Answer

Blood type

Question 4

A data set contains the following variables: age, gender, income, and education level. Which of these variables is best classified as ordinal categorical?

Accepted Answer

Education level (e.g., high school, college, graduate school)

Question 5

Which sampling method is being used if a researcher divides a city into neighborhoods, randomly selects 5 neighborhoods, and surveys every household in those neighborhoods?

Accepted Answer

Cluster sampling

Question 6

In a study, a researcher first divides a population into males and females, then randomly selects 50 individuals from each group. What type of sampling is this?

Accepted Answer

Stratified sampling

Question 7

Which of the following best describes a continuous quantitative variable?

Accepted Answer

A variable that can take any value within a given range, such as height or weight.

Question 8

A hospital wants to estimate the average length of stay for patients. They use a list of all patients discharged in the last year and randomly select 100 patients to review. What type of sampling is this?

Accepted Answer

Simple random sampling

Question 9

Which of the following is an example of an observational study?

Accepted Answer

A researcher records the blood pressure of patients without giving any treatment.

Question 10

In an experiment testing a new medication, what is the purpose of the control group?

Accepted Answer

To provide a baseline for comparison by not receiving the treatment.

Question 11

Which of the following best describes a double-blind experiment?

Accepted Answer

Neither the subjects nor the researchers know which group the subjects are in.

Question 12

A researcher wants to study the effect of a new fertilizer on plant growth. She randomly assigns 50 plants to receive the fertilizer and 50 plants to receive no fertilizer. What is the explanatory variable in this experiment?

Accepted Answer

Whether or not the plant received fertilizer

Question 13

Which of the following is an example of discrete quantitative data?

Accepted Answer

Number of cars owned by a family

Question 14

A survey asks respondents to rate their satisfaction on a scale from 1 (very dissatisfied) to 5 (very satisfied). What type of data is this?

Accepted Answer

Ordinal categorical

Question 15

Which of the following best describes a census?

Accepted Answer

The collection of data from all cases of a population.

Question 16

A researcher wants to study the average test scores of high school students in a large city. She divides the city into districts, randomly selects 3 districts, then randomly selects 5 schools from each district, and finally randomly selects 20 students from each school. What type of sampling is this?

Accepted Answer

Multistage sampling

Question 17

Which of the following is a key difference between stratified and cluster sampling?

Accepted Answer

Stratified sampling selects random samples from each subgroup, while cluster sampling selects entire subgroups.

Question 18

Suppose you have a data matrix with 100 rows and 10 columns. What do the rows and columns represent?

Accepted Answer

Rows represent observation units (cases), columns represent variables.

Question 19

Which of the following is an example of using available data?

Accepted Answer

Analyzing census data collected five years ago to study current trends.

Question 20

A researcher wants to know if a new teaching method improves student performance. She randomly assigns students to either the new method or the traditional method and compares their test scores. What type of study is this?

Accepted Answer

Experiment

Introduction to Statistics: Data, Variables, and Sampling Methods

Guida di studio - Domande di pratica

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