Question 1

A pharmaceutical company claims its new drug increases average IQ by 3 points, with a 25% chance of this result occurring by random chance. Which of the following best describes the statistical and practical significance of this result?

Accepted Answer

The result is not statistically significant and not practically significant.

Question 2

Which of the following is an example of a parameter?

Accepted Answer

The percentage of all registered voters in a country who voted in the last election.

Question 3

A study collects the number of cars owned by each household in a city. What type of data is this?

Accepted Answer

Discrete quantitative data

Question 4

A researcher wants to study the effect of a new teaching method on student performance. She randomly assigns students to two groups: one receives the new method, the other the standard method. What type of study is this?

Accepted Answer

Experiment

Question 5

Which of the following best illustrates the concept that 'correlation does not imply causation'?

Accepted Answer

A study finds a strong association between ice cream sales and drowning incidents.

Question 6

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 7

Which sampling method is most likely to introduce bias?

Accepted Answer

Voluntary response sampling

Question 8

A study records the lengths of fish caught in a lake, measured to the nearest millimeter. What is the level of measurement for this data?

Accepted Answer

Ratio

Question 9

A frequency distribution table for test scores has class intervals of 10 points each, starting at 50. What is the class midpoint for the interval 60–69?

Accepted Answer

$$65$$

Question 10

A bar graph is most appropriate for displaying which type of data?

Accepted Answer

Categorical data

Question 11

A researcher wants to estimate the average commute time for all employees at a large company. She divides employees into departments and randomly selects 5 employees from each department. What sampling method is she using?

Accepted Answer

Stratified sampling

Question 12

Which of the following is an example of a statistic?

Accepted Answer

The median income of a random sample of 200 households

Question 13

A study finds a linear correlation coefficient $$r = 0.85$$ between hours studied and exam scores. What does this indicate?

Accepted Answer

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

Question 14

A researcher collects the eye colors of 1000 people. What is the level of measurement for this data?

Accepted Answer

Nominal

Question 15

Which of the following best describes a double-blind experiment?

Accepted Answer

Neither the subjects nor the researchers know who receives the treatment or placebo.

Question 16

A frequency polygon is constructed by plotting which of the following?

Accepted Answer

Class midpoints versus frequencies

Question 17

A study uses a convenience sample to survey opinions about a new city law. Which of the following is a likely consequence?

Accepted Answer

The results may be biased and not generalizable to the population.

Question 18

A regression equation is given by $$\hat{y} = 2 + 3x. $$What is the predicted value of $$y$$ when $$x = 4$$?

Accepted Answer

$$14$$

Question 19

Which of the following is an example of a retrospective study?

Accepted Answer

A researcher examines medical records from the past 20 years to study disease trends.

Question 20

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

Accepted Answer

$$577$$

Foundations of Statistics: Data, Sampling, and Experimental Design

Guida di studio - Domande di pratica

Study guide - Flashcard