Question 1

Which of the following best describes the main goal of statistics?

Accepted Answer

To organize, summarize, and analyze information to draw conclusions and provide a measure of confidence in those conclusions.

Question 2

A researcher wants to know the average commute time for all employees at a large company. She surveys 50 randomly selected employees and finds an average commute time of 32 minutes. Which term best describes the value 32 minutes?

Accepted Answer

Statistic

Question 3

Which of the following variables is qualitative?

Accepted Answer

Favorite type of cuisine

Question 4

A variable that can take on any value within an interval, such as the exact time a runner finishes a marathon, is best described as:

Accepted Answer

Continuous

Question 5

Which level of measurement allows for meaningful ratios and has a true zero?

Accepted Answer

Ratio

Question 6

A study follows a group of patients over 10 years to observe the development of heart disease. This is an example of which type of observational study?

Accepted Answer

Cohort study

Question 7

In a clinical trial, neither the patients nor the doctors know who receives the actual medication and who receives a placebo. This is an example of:

Accepted Answer

Double-blind experiment

Question 8

A researcher divides a city into neighborhoods, randomly selects 5 neighborhoods, and surveys every household in those neighborhoods. What sampling method is this?

Accepted Answer

Cluster sampling

Question 9

Which of the following is a source of response bias in a survey?

Accepted Answer

Misrepresented answers due to poorly worded questions

Question 10

Suppose a sample is obtained by selecting every 10th person entering a store, starting with the 3rd person. If the population size is $$N = 500$$ and the sample size is $$n = 50$$, what is the value of $$k in $$systematic sampling?

Accepted Answer

$$k = 10$$

Question 11

A researcher wants to compare the effect of two diets on weight loss. She matches participants by age and gender, then randomly assigns one from each pair to each diet. This is an example of:

Accepted Answer

Matched-pairs design

Question 12

Which of the following best describes sampling bias?

Accepted Answer

When the sampling technique favors one part of the population over another

Question 13

A variable that classifies students by their letter grade (A, B, C, D, F) is at which level of measurement?

Accepted Answer

Ordinal

Question 14

Which of the following is NOT a characteristic of a well-designed experiment?

Accepted Answer

Convenience sampling of experimental units

Question 15

A survey is sent to 1,000 randomly selected people, but only 200 respond. If those who respond have different opinions than those who do not, this is an example of:

Accepted Answer

Nonresponse bias

Question 16

Which of the following best describes a stratified sample?

Accepted Answer

Dividing the population into homogeneous groups and randomly selecting individuals from each group

Question 17

In the context of experiments, what is a placebo?

Accepted Answer

A harmless, inactive treatment used to compare against the actual treatment

Question 18

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

Accepted Answer

The number of cars in a parking lot

Question 19

A researcher collects data on the number of hours students study per week and their final exam scores. Which variable is the explanatory variable?

Accepted Answer

Number of hours studied

Question 20

Which of the following errors can occur even in a complete census?

Accepted Answer

Nonsampling error

Chapter 1: Data Collection and Introduction to Statistics

Guida di studio - Domande di pratica

Study guide - Flashcard