Question 1

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

Accepted Answer

A parameter describes a characteristic of a population, while a statistic describes a characteristic of a sample.

Question 2

A researcher wants to study the effect of a new drug on blood pressure. She randomly assigns 100 patients to receive either the drug or a placebo and measures their blood pressure after 6 months. What type of study is this?

Accepted Answer

Experiment

Question 3

Which sampling method involves dividing the population into subgroups with similar characteristics and then randomly sampling from each subgroup?

Accepted Answer

Stratified sampling

Question 4

A survey asks respondents to report their own weight. Which potential pitfall in data collection does this scenario illustrate?

Accepted Answer

Sample data reported instead of measured

Question 5

Which of the following is an example of continuous data?

Accepted Answer

The height of students measured in centimeters

Question 6

A poll conducted online allows anyone to participate. What type of sample is this, and what is a major concern with this method?

Accepted Answer

Voluntary response sample; concern is bias due to self-selection

Question 7

Which level of measurement is characterized by data that can be ordered, but differences between values are not meaningful?

Accepted Answer

Ordinal

Question 8

In a clinical trial, neither the subjects nor the experimenters know who receives the treatment or placebo. What is this technique called?

Accepted Answer

Double-blind

Question 9

A study finds that a new diet leads to an average weight loss of 2.1 kg over one year, which is statistically significant. However, many participants feel this amount is not worth the effort. What concept does this illustrate?

Accepted Answer

Practical significance

Question 10

Which of the following is a correct definition of a simple random sample?

Accepted Answer

A sample where every possible sample of the same size has the same chance of being chosen.

Question 11

A researcher collects data on the years in which historical events occurred: 1492, 1776, 2000. What is the level of measurement for these data?

Accepted Answer

Interval

Question 12

Which of the following is an example of a confounding variable in a study examining the relationship between ice cream sales and drowning rates?

Accepted Answer

The temperature during summer months

Question 13

A sample is selected by choosing every 5th person from a list. What type of sampling is this?

Accepted Answer

Systematic sampling

Question 14

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

Accepted Answer

Entering data incorrectly during analysis

Question 15

A study collects data from medical records of patients treated in the past 10 years. What type of observational study is this?

Accepted Answer

Retrospective (case-control) study

Question 16

Which of the following best describes the ratio level of measurement?

Accepted Answer

Data can be ordered, differences are meaningful, and there is a natural zero point.

Question 17

A researcher deletes all subjects with missing values from her dataset. What is this method called?

Accepted Answer

Delete cases

Question 18

Which of the following is an example of discrete data?

Accepted Answer

The number of books on a shelf

Question 19

A study collects data on the gender of professional athletes. What type of data is this?

Accepted Answer

Categorical (qualitative) data

Question 20

A pollster divides a city into neighborhoods, randomly selects several neighborhoods, and surveys all residents in those neighborhoods. What sampling method is being used?

Accepted Answer

Cluster sampling

Introduction to Statistics: Concepts, Data Types, and Sampling Methods

Guida di studio - Domande di pratica

Study guide - Flashcard