Question 1

Which of the following best describes the difference between descriptive and inferential statistics?

Accepted Answer

Descriptive statistics summarize features of the data set, while inferential statistics allow conclusions to be drawn about populations from samples.

Question 2

A researcher wants to study the average BMI of adults in a city. She randomly selects 200 adults from the city’s population. What is the sample in this scenario?

Accepted Answer

The 200 randomly selected adults.

Question 3

Why do researchers use samples instead of investigating entire populations?

Accepted Answer

Samples are easier, quicker, and cheaper to study than populations.

Question 4

Which of the following is a parameter?

Accepted Answer

The standard deviation of a population.

Question 5

In simple random sampling, what is the key feature that distinguishes it from other sampling methods?

Accepted Answer

Every member of the population has an equal chance of being selected.

Question 6

A study on sleep habits recruits participants from a local gym because they are readily available. Which sampling method is being used?

Accepted Answer

Opportunity sampling

Question 7

Which sampling method is most likely to introduce bias because participants refer others to the study?

Accepted Answer

Snowball sampling

Question 8

A researcher advertises a study and waits for people to respond and volunteer. What is a major disadvantage of this sampling method?

Accepted Answer

It may introduce bias and not provide a representative sample.

Question 9

Which of the following best describes a null hypothesis ($$H_0) in $$statistical testing?

Accepted Answer

A statement that there is no difference between groups or treatments.

Question 10

What is a Type I error in hypothesis testing?

Accepted Answer

Rejecting a true null hypothesis.

Question 11

A researcher tests whether a new drug is more effective than a placebo. The null hypothesis is that there is no difference. If the researcher incorrectly concludes the drug is effective when it is not, what type of error has occurred?

Accepted Answer

Type I error

Question 12

Which of the following statements about confidence intervals is correct?

Accepted Answer

A confidence interval presents a range of values within which we are confident the population mean will fall.

Question 13

If a 95% confidence interval for the mean blood pressure in a population is $$[120, 130]$$, what does this mean?

Accepted Answer

We are 95% confident that the true population mean lies between 120 and 130.

Question 14

Which formula is used to calculate the margin of error for a confidence interval for the mean when the population standard deviation is known?

Accepted Answer

$$E = z^* \frac{\sigma}{\sqrt{n}}$$

Question 15

A researcher wants to estimate the mean cholesterol level in adults. She collects a sample and calculates a 95% confidence interval. What will happen to the width of the confidence interval if she increases the sample size?

Accepted Answer

The confidence interval will become narrower.

Question 16

Which of the following is NOT a step in simple random sampling?

Accepted Answer

Select participants based on convenience.

Question 17

In hypothesis testing, what does a p-value less than 0.05 typically indicate?

Accepted Answer

There is strong evidence against the null hypothesis.

Question 18

Which sampling method is most appropriate for studying a hidden population, such as people experiencing a rare disease?

Accepted Answer

Snowball sampling

Question 19

A researcher uses SPSS to calculate a 95% confidence interval for the mean. What does the lower and upper limit of the interval represent?

Accepted Answer

The range within which the population mean is likely to fall with 95% confidence.

Applied Statistics for the Health Sciences: Core Concepts and Methods

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