Question 1

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

Accepted Answer

Descriptive statistics involves summarizing and presenting data, while inferential statistics involves making generalizations about a population based on sample data.

Question 2

A researcher wants to estimate the average waiting time at a drive-through window. She records the waiting times for every customer over a 7-day period. What is the sample in this study?

Accepted Answer

The waiting times of all customers who visited the drive-through during the 7-day period.

Question 3

Which of the following is an example of a qualitative variable?

Accepted Answer

The species of fish (e.g., channel catfish, largemouth bass, smallmouth buffalo).

Question 4

A simple random sample is defined as:

Accepted Answer

A sample where every possible sample of a given size has an equal chance of being selected.

Question 5

Which of the following best describes selection bias?

Accepted Answer

When a subset of the population is excluded so that these units have no chance of being selected.

Question 6

A company wants to know the average age of its customers. It surveys a random sample of 500 customers and finds an average age of 35 years, with a bound on the error of estimation of 2 years. Which of the following statements is correct?

Accepted Answer

We can be reasonably certain that the true average age of all customers is between 33 and 37 years.

Question 7

Which of the following is NOT a type of random sampling method?

Accepted Answer

Convenience sampling

Question 8

In a designed experiment, what is the main characteristic that distinguishes it from an observational study?

Accepted Answer

The researcher exerts strict control over the characteristics of the experimental units.

Question 9

Suppose you want to estimate the average income of households in a city. You divide the city into neighborhoods and randomly select some neighborhoods, then survey every household in those neighborhoods. What sampling method are you using?

Accepted Answer

Cluster sampling

Question 10

Which of the following equations correctly represents the relationship between a population parameter and a sample statistic?

Accepted Answer

$$\mu is $$estimated by $$\overline{x}$$

Question 11

A survey is sent to 1,000 randomly selected online shoppers, but only 400 respond. Which type of bias is most likely present?

Accepted Answer

Nonresponse bias

Question 12

Which of the following is an example of quantitative data?

Accepted Answer

The number of female executives in a company.

Question 13

A process is best described as:

Accepted Answer

A series of actions or operations that transforms inputs to outputs.

Question 14

Which of the following best describes the purpose of business analytics in statistics?

Accepted Answer

To extract useful information from data in order to make better business decisions.

Question 15

A researcher wants to study the effect of a new fertilizer on plant growth. She randomly assigns some plants to receive the fertilizer and others to receive none, then measures their growth. This is an example of:

Accepted Answer

A designed experiment

Question 16

Which of the following is a measure of reliability in statistical inference?

Accepted Answer

A bound on the error of estimation

Question 17

A pollster asks a sensitive question and uses a randomized response technique to collect answers. What is the main advantage of this method?

Accepted Answer

It increases the likelihood of obtaining truthful responses.

Question 18

Which of the following is an example of measurement error?

Accepted Answer

A survey question is worded ambiguously, leading to inaccurate responses.

Question 19

In the context of statistical thinking, why is it important to recognize that variation exists in populations and process data?

Accepted Answer

Because recognizing variation helps in making more accurate inferences and decisions.

Question 20

Suppose you want to select every 10th person from a list of 1,000 employees to participate in a survey. What sampling method are you using?

Accepted Answer

Systematic sampling

Chapter 1: Statistics, Data, and Statistical Thinking – Study Notes

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