Question 1

A pharmaceutical company wants to test a new drug for lowering blood pressure. They randomly assign 200 patients to receive either the new drug or a placebo, without telling the patients or the researchers which group each patient is in. What type of experimental design is this?

Accepted Answer

Double-blind randomized controlled trial

Question 2

Which of the following best describes a parameter?

Accepted Answer

A numerical measurement describing some characteristic of a population

Question 3

A survey asks, 'Do you support the development of atomic weapons that could kill millions of innocent people?' What is the main flaw in this question?

Accepted Answer

It is a loaded question

Question 4

A study finds a strong positive correlation between the number of ice creams sold and the number of drowning incidents in a city. Which of the following is the best conclusion?

Accepted Answer

There is a lurking variable, such as temperature, that affects both variables

Question 5

Which of the following data types is best described as discrete quantitative data?

Accepted Answer

The number of cars passing through a toll booth each hour

Question 6

A researcher records the number of students who pass each of their courses. What is the level of measurement for this data?

Accepted Answer

Ratio

Question 7

A polling company reports that 57% of 1013 surveyed adults say that secondhand smoke is 'very harmful.' What is the exact value that is 57% of 1013, rounded to the nearest whole number?

Accepted Answer

$$577$$

Question 8

Which sampling method is most likely to result in a biased sample?

Accepted Answer

Voluntary response sample

Question 9

A frequency distribution table for test scores has class boundaries of $$60.5-70.5$$, $$70.5-80.5$$, $$80.5-90.5$$, and $$90.5-100.5. $$What is the class width?

Accepted Answer

$$10$$

Question 10

A study of 400 babies born at four different hospitals in New York State found that 51% of the babies were girls. Is the value 51% a statistic or a parameter?

Accepted Answer

Statistic

Question 11

Which of the following is an example of continuous data?

Accepted Answer

The time it takes to run a marathon

Question 12

A researcher wants to compare the effects of a new teaching method on math scores. She divides students into groups based on their previous math grades and then randomly assigns treatments within each group. What type of experimental design is this?

Accepted Answer

Randomized block design

Question 13

If a histogram of exam scores is approximately symmetric and bell-shaped, which distribution does it most closely resemble?

Accepted Answer

Normal distribution

Question 14

A study reports a linear correlation coefficient of $$r = 0.85$$ between hours studied and exam scores. Which of the following is the best interpretation?

Accepted Answer

There is a strong positive linear relationship between hours studied and exam scores

Question 15

A regression equation is given by $$\displaystyle \hat{y} = 50 + 2x. $$What is the predicted value of $$y$$ when $$x = 10$$?

Accepted Answer

$$70$$

Question 16

Which of the following is NOT a requirement for constructing a valid frequency distribution for quantitative data?

Accepted Answer

Classes must overlap

Question 17

A researcher collects data on the number of siblings each student has. What is the most appropriate level of measurement for this data?

Accepted Answer

Ratio

Question 18

A study uses a convenience sample to survey students in a university cafeteria about their eating habits. What is the main limitation of this sampling method?

Accepted Answer

It is likely to be biased and not representative of the population

Question 19

A time series graph is most appropriate for which type of data?

Accepted Answer

Data showing changes in a variable over time

Question 20

A study finds that a new diet leads to an average weight loss of 2 kg with a $$p-$$value of $$0.25. $$What can you conclude about the statistical and practical significance of the result?

Accepted Answer

The result is not statistically significant and may not be practically significant

Foundations of Statistics: Data, Sampling, and Experimental Design

Guida di studio - Domande di pratica

Study guide - Flashcard