Q: If a survey of 1000 randomly selected births finds that 5 are twins, what is the estimated percentage of twin births?

$$ \frac{5}{1000} \times 100 = 0.5\% $$

Question 1

Which of the following best describes a voluntary response sample?

Accepted Answer

A sample in which respondents themselves decide whether to participate.

Question 2

A survey posted on a news website asking readers to respond is most likely to suffer from which type of bias?

Accepted Answer

Voluntary response bias

Question 3

In a study, 70% of respondents said they "always" wash their hands in public restrooms. Why might this reported rate be higher than the true rate?

Accepted Answer

Respondents may be ashamed to say they do not always wash their hands.

Question 4

Which of the following is the best definition of a population in statistics?

Accepted Answer

The complete collection of all measurements or data that are being considered.

Question 5

Suppose a bar chart visually exaggerates the difference between two groups by starting the vertical axis at 60% instead of 0%. What is the main reason this is deceptive?

Accepted Answer

It visually inflates the difference between the groups.

Question 6

A study finds that getting a car tune-up increases gas mileage by 2 miles per gallon, but the cost of the tune-up is $200. Which statement is most accurate?

Accepted Answer

The result is statistically significant but not practically significant.

Question 7

Which of the following is an example of a reputable source for statistical data?

Accepted Answer

A peer-reviewed journal article.

Question 8

In the process of a statistical study, which step comes immediately after preparing the context and collecting the data?

Accepted Answer

Analyze

Question 9

A random sample is important in statistics because:

Accepted Answer

It reduces bias and makes the sample representative of the population.

Question 10

If a survey of 1000 randomly selected births finds that 5 are twins, what is the estimated percentage of twin births?

Accepted Answer

$$ \frac{5}{1000} 	imes 100 = 0.5\% $$

Question 11

Which of the following best describes statistical significance?

Accepted Answer

A result that is unlikely to have occurred by chance.

Question 12

A census is:

Accepted Answer

The complete collection of data from every member of the population.

Question 13

Which of the following is a potential problem with using internet polls for statistical studies?

Accepted Answer

They often result in voluntary response bias.

Question 14

In a study, the sample is defined as:

Accepted Answer

The subset of the population from which data are actually collected.

Question 15

A bar chart shows 65% of respondents prefer printed books and 35% prefer electronic books. If the vertical axis starts at 60%, what is the ratio of people preferring printed to electronic books?

Accepted Answer

$$ \frac{65}{35} \approx 1.86 $$

Question 16

Which of the following is an example of practical significance?

Accepted Answer

A result that is both statistically significant and has a meaningful impact in practice.

Question 17

A reputable source is important in statistics because:

Accepted Answer

It increases the credibility and reliability of the results.

Question 18

If a survey uses a sample of 186,000 respondents, this is an example of:

Accepted Answer

A large sample

Question 19

Which of the following is NOT a step in the process of a statistical study?

Accepted Answer

Ignore the context

Question 20

A study finds that increasing the likelihood of a gain from 50% to 52% is statistically significant but not practically significant. Why?

Accepted Answer

Because the increase is too small to matter in real life.

Introduction to Statistics: Data Collection, Surveys, and Statistical Thinking

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