Question 1

Which of the following best describes the main goal of statistics?

Accepted Answer

To describe and understand sources of variability in data and provide a measure of confidence in conclusions.

Question 2

A researcher wants to estimate the average salary of all employees in a large company. She randomly selects 60 employees and finds their average salary is $55,000. In this context, what is the sample?

Accepted Answer

The 60 employees selected for the study.

Question 3

Which of the following is an example of a parameter?

Accepted Answer

The proportion of all registered voters in a city who voted in the last election.

Question 4

Which of the following variables is qualitative?

Accepted Answer

Type of payment method used (credit card, cash, phone).

Question 5

A variable that can take on any value within a given range and can be measured to any desired level of accuracy is called:

Accepted Answer

A continuous variable.

Question 6

In a study, researchers survey 1,000 adults about their annual income to estimate the mean income of all adults in a city. What is the population in this study?

Accepted Answer

All adults in the city.

Question 7

Which of the following best describes a simple random sample?

Accepted Answer

A sample where every possible subset of the population has an equally likely chance of being selected.

Question 8

A school wants to select 5 students out of 100 for a survey. Which method ensures a simple random sample?

Accepted Answer

Numbering all students from 1 to 100 and using a random number generator to select 5 unique numbers.

Question 9

Which of the following scenarios is most likely to result in a biased sample?

Accepted Answer

Surveying only people in one neighborhood to represent an entire city.

Question 10

A study records the number of days per week a student eats school lunch. What type of variable is this?

Accepted Answer

Quantitative and discrete.

Question 11

Which of the following is an example of inferential statistics?

Accepted Answer

Using a sample mean to estimate the mean of the entire population.

Question 12

A researcher wants to know if a new teaching method improves test scores. She randomly assigns students to two groups: one uses the new method, the other uses the traditional method. What type of study is this?

Accepted Answer

Experimental study.

Question 13

Which of the following is NOT a step in the process of statistics?

Accepted Answer

Ignore the reliability of the results.

Question 14

A city wants to estimate the average commute time of its residents. They survey only people at a downtown coffee shop during weekday mornings. What is the most likely problem with this sampling method?

Accepted Answer

It is likely to be biased because it does not represent all residents.

Question 15

Which of the following best describes a discrete variable?

Accepted Answer

A variable that has a finite or countable number of possible values.

Question 16

A researcher lists all 500 members of a club and uses a random number generator to select 20 members for a survey. What is the purpose of numbering the members before selection?

Accepted Answer

To ensure each member has an equal chance of being selected.

Question 17

In a study, the variable 'payment amount for street parking' is recorded. What type of variable is this?

Accepted Answer

Quantitative and continuous.

Question 18

A club wants to select 4 out of 25 members for a panel. Which of the following methods does NOT produce a simple random sample?

Accepted Answer

Listing the members alphabetically and taking the first 4 names.

Question 19

Which of the following statements about data is TRUE?

Accepted Answer

Data are characteristics of individuals and can vary.

Question 20

Suppose you want to estimate the average number of hours students at your university study per week. Which sampling method would most likely yield a representative sample?

Accepted Answer

Randomly selecting students from the entire student directory.

Elementary Statistics: Chapter 1 – Data Collection and Statistical Thinking

Guida di studio - Domande di pratica

Study guide - Flashcard