Question 1

Which of the following best describes the difference between a population and a sample in statistics?

Accepted Answer

A population is the entire set of subjects of interest, while a sample is a subset selected from the population.

Question 2

A researcher wants to estimate the average commute time for all employees in a large company. She randomly selects 200 employees and calculates their average commute time. In this scenario, what is the parameter?

Accepted Answer

The average commute time of all employees in the company.

Question 3

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

Accepted Answer

Favorite color

Question 4

Suppose a survey of 1,000 state residents finds that 20% support a change to the state flag. The state claims that 15% of all residents support the change. In this context, what is the statistic?

Accepted Answer

The proportion of the 1,000 surveyed residents who support the change.

Question 5

Which of the following best describes inferential statistics?

Accepted Answer

Methods for making decisions or predictions about a population based on data from a sample.

Question 6

A company database contains records for every employee. If you calculate the median income from this database, what is the result called?

Accepted Answer

A parameter

Question 7

Which of the following is a continuous quantitative variable?

Accepted Answer

Commute time (in hours)

Question 8

Why is it often impractical to collect data from every item in a population?

Accepted Answer

It takes more time, costs more money, and makes it harder to manage the data.

Question 9

A study claims that 25% of all students would do homework even if it was not graded. A random sample of 500 students is taken, and 60% say they would do the assignment. In this scenario, what is the sample?

Accepted Answer

The 500 students surveyed.

Question 10

Which of the following is NOT a reason to use a sample instead of a population?

Accepted Answer

Sampling always gives the exact same results as studying the population.

Question 11

If you want to make a conclusion about every item in a population, what is the best way to do so?

Accepted Answer

Look at all (every) items in the population.

Question 12

Which of the following is an example of a discrete quantitative variable?

Accepted Answer

Number of absences

Question 13

Suppose you want to know the average age of all SC residents. You collect data from a sample of 20,000 residents. What is the population in this scenario?

Accepted Answer

All SC residents.

Question 14

Which of the following statements about variables is TRUE?

Accepted Answer

A variable is a characteristic or property that can take on different values for different subjects.

Question 15

A survey asks respondents to select their preferred type of transportation: car, bus, bike, or walk. What type of variable is being measured?

Accepted Answer

Categorical variable

Question 16

Which of the following is a correct application of inference in statistics?

Accepted Answer

Calculating the mean commute time for a sample and using it to predict the mean for all employees.

Question 17

Which formula would you use to calculate the mean ($$\mu) of a $$population with $$N$$ values $$x_1$$, $$x_2$$, ..., x_N$$?

Accepted Answer

$$\mu = \dfrac{\sum_{i=1}^{N} x_i}{N}$$

Question 18

A researcher collects data on the number of sick days taken by employees in a year. Which type of variable is this?

Accepted Answer

Discrete quantitative variable

Question 19

Which of the following best describes descriptive statistics?

Accepted Answer

Methods for summarizing and describing the features of a dataset.

Question 20

A study finds that the mean age of a sample of 1,000 SC residents is 35 years. Which term best describes this value?

Accepted Answer

Statistic

Introduction to Statistics: Populations, Samples, and Variables

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