Question 1

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

Accepted Answer

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

Question 2

In a study investigating the effect of school start time on sleep duration, researchers randomly selected 383 adolescents. Which step of the statistical process does this action represent?

Accepted Answer

Collecting the data

Question 3

Which of the following variables is both quantitative and continuous?

Accepted Answer

Daily intake of whole grains (measured in grams per day)

Question 4

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

Accepted Answer

Designed experiment

Question 5

Which sampling method involves dividing the population into homogeneous groups and then taking a simple random sample from each group?

Accepted Answer

Stratified sampling

Question 6

Suppose you want to select a sample of 20 bottles from a production line using systematic sampling. If the population size is 200, what is the value of $$k$$?

Accepted Answer

$$k = \frac{200}{20} = 10$$

Question 7

Which of the following is an example of response bias in a survey?

Accepted Answer

Survey respondents misrepresenting their answers due to question wording

Question 8

A variable is at the ratio level of measurement if:

Accepted Answer

It has the properties of the interval level and ratios of values have meaning, with zero representing the absence of the quantity.

Question 9

In a matched-pairs design, which of the following is true?

Accepted Answer

Experimental units are paired up based on some relationship, and there are only two levels of treatment.

Question 10

Which of the following best illustrates the concept of confounding in an experiment?

Accepted Answer

A study finds that caffeine and sleep both affect reaction time, but cannot distinguish which is responsible for faster reaction times.

Question 11

Which of the following is NOT a source of bias in sampling?

Accepted Answer

Randomization bias

Question 12

In the context of statistical studies, what is a lurking variable?

Accepted Answer

A variable not considered in the study but that affects the value of the response variable.

Question 13

Which of the following best describes a cluster sample?

Accepted Answer

Divide the population into groups, randomly select some groups, and survey all individuals in those groups.

Question 14

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

Accepted Answer

Gender

Question 15

A study tracks a group of adolescents with prehypertension over several years to assess which health factors lead to hypertension. What type of observational study is this?

Accepted Answer

Cohort study

Question 16

Which equation is used to determine the value of $$k in $$systematic sampling?

Accepted Answer

$$k = \frac{N}{n}$$

Question 17

In a double-blind experiment, who is unaware of which treatment is being administered?

Accepted Answer

Both the experimental unit and the researcher in contact with the unit

Question 18

Which of the following is a real-world example of sampling bias?

Accepted Answer

A poll conducted only among landline phone users, excluding cell phone users.

Question 19

Which step in designing an experiment involves randomly assigning experimental units to treatment groups?

Accepted Answer

Randomization

Question 20

Which of the following best describes inferential statistics?

Accepted Answer

Using methods that take results from a sample, extend them to the population, and measure the reliability of the result.

Chapter 1: Data Collection – Foundations of Statistical Practice

Guida di studio - Domande di pratica

Study guide - Flashcard