Question 1

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

Accepted Answer

A parameter is a numerical summary based on a population, while a statistic is based on a sample.

Question 2

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

Accepted Answer

Designed experiment

Question 3

Which sampling method involves dividing the population into homogeneous groups and then randomly selecting individuals from each group?

Accepted Answer

Stratified sampling

Question 4

A variable is measured as the number of children in a household. What type of variable is this?

Accepted Answer

Discrete quantitative variable

Question 5

Which of the following is an example of a lurking variable in a study examining the relationship between exercise and heart disease?

Accepted Answer

Dietary habits not measured in the study

Question 6

In a systematic sample, if the population size $$N = 1000$$ and the desired sample size $$n = 50$$, what is the value of $$k$$?

Accepted Answer

$$k = 20$$

Question 7

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

Accepted Answer

Ratio

Question 8

A survey is conducted by asking people leaving a grocery store about their shopping habits. What type of sampling is this?

Accepted Answer

Convenience sampling

Question 9

Which of the following is a source of response bias?

Accepted Answer

Misrepresented answers

Question 10

In a matched-pairs design, what is the primary reason for pairing experimental units?

Accepted Answer

To control for variables that may affect the response variable

Question 11

A study tracks 1.2 million people over 20 years to examine the relationship between lifestyle factors and cancer. What type of observational study is this?

Accepted Answer

Cohort study

Question 12

Which of the following best describes a cluster sample?

Accepted Answer

Randomly select groups and include all individuals from those groups

Question 13

A researcher wants to compare test scores between men and women in two types of English courses. She randomly assigns half of the men and half of the women to each course. What type of experimental design is this?

Accepted Answer

Randomized block design

Question 14

Which of the following is NOT a source of nonsampling error?

Accepted Answer

Using a sample instead of a population

Question 15

In the process of statistics, which step involves extending sample results to the population and reporting reliability?

Accepted Answer

Performing inference

Question 16

A variable is measured as 'class rank' (Freshman, Sophomore, Junior, Senior). What is the level of measurement?

Accepted Answer

Ordinal

Question 17

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

Accepted Answer

Daily intake of whole grains (grams per day)

Question 18

What is the main purpose of randomization in an experiment?

Accepted Answer

To minimize the effects of uncontrolled variables

Question 19

Which of the following best describes a simple random sample?

Accepted Answer

Every possible sample of size $$n$$ has an equally likely chance of occurring.

Question 20

A study finds that students who eat breakfast score higher on tests, but does not account for socioeconomic status. What is the likely issue with this study?

Accepted Answer

Confounding due to a lurking variable

Introductory Statistics: Data Collection and Experimental Design

Guida di studio - Domande di pratica

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