Question 1

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

Accepted Answer

A parameter describes a population, while a statistic describes a sample.

Question 2

A hospital administrator wants to estimate the average length of stay for all patients in the hospital last year. She randomly selects 150 patient records and calculates the average length of stay for these patients. In this context, what is the population?

Accepted Answer

All patients in the hospital last year.

Question 3

Which of the following is an example of inferential statistics?

Accepted Answer

Using a sample to estimate the proportion of all Americans who support a new healthcare policy.

Question 4

Suppose a poll reports that 60% of a random sample of 1,000 voters support a new law, with a margin of error of ±3% at the 95% confidence level. What is the correct 95% confidence interval for the proportion of all voters who support the law?

Accepted Answer

$$(57\%, 63\%)$$

Question 5

Which of the following statements about random sampling is TRUE?

Accepted Answer

Random sampling is used to make the sample representative of the population.

Question 6

A researcher collects data on the blood pressure of 500 randomly selected adults in a city. She finds the mean systolic blood pressure to be 122 mmHg. What is this value an example of?

Accepted Answer

A statistic.

Question 7

Which of the following best describes the purpose of descriptive statistics?

Accepted Answer

To summarize and organize data using graphs and numerical measures.

Question 8

A news article reports: 'A survey of 2,000 Americans found that 66% believe global trade is good for the US economy.' What is the sample in this study?

Accepted Answer

The 2,000 Americans surveyed.

Question 9

Which of the following is NOT a typical step in a data science project?

Accepted Answer

Ignoring ethical issues such as data privacy.

Question 10

A pharmaceutical company wants to test whether a new drug is more effective than the current standard. They randomly assign patients to receive either the new drug or the standard treatment and compare recovery rates. Which statistical concept is most important for ensuring the validity of their results?

Accepted Answer

Random assignment of patients to treatment groups.

Question 11

If a sample of 1,013 adults is used to estimate a population proportion, what is the approximate margin of error at the 95% confidence level using the formula $$\frac{1}{\sqrt{n}} 	imes 100\%$$?

Accepted Answer

$$3.14\%$$

Question 12

Which of the following is an example of a variable in a statistical study?

Accepted Answer

The characteristic being measured, such as age or blood pressure.

Question 13

A confidence interval for a population mean is calculated as $$\bar{x} \pm$$ margin of error. If $$\bar{x} = 50$$ and the margin of error is $$5$$, what is the confidence interval?

Accepted Answer

$$(45, 55)$$

Question 14

Which of the following is a potential ethical issue in data science?

Accepted Answer

Algorithmic bias.

Question 15

A researcher wants to know if a new teaching method improves test scores. She randomly assigns students to either the new method or the traditional method and compares their average scores. Which type of statistical method is she using?

Accepted Answer

Inferential statistics.

Question 16

Which of the following best describes the role of a margin of error in a statistical estimate?

Accepted Answer

It quantifies the uncertainty associated with a sample estimate.

Question 17

In a spreadsheet data file, what does each row typically represent?

Accepted Answer

A case or observation.

Question 18

Which of the following is a reason why statistical software alone is not sufficient for proper data analysis?

Accepted Answer

Statistical software may perform analyses that are not appropriate for the data.

Question 19

A study finds that 84.79% of all EKU students were undergraduates in Fall 2023. A random sample of 200 students finds 83.50% are undergraduates. What is 83.50% in this context?

Accepted Answer

A statistic.

Question 20

Which of the following best describes the concept of statistical significance?

Accepted Answer

A result that is so extreme it would rarely be observed by chance.

Chapter 1: Statistics – The Art and Science of Learning from Data

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