Q: If a data set consists of the following values: 2, 4, 6, 8, what is the percentage of values greater than 4?

$$\frac{2}{4} \times 100 = 50\%$$

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 group of interest, while a sample is a subset of that group.

Question 2

A researcher wants to study the average height of all students at a university. She measures the height of 200 randomly selected students. In this context, what is the statistic?

Accepted Answer

The average height calculated from the 200 students measured.

Question 3

Which of the following is an example of a loaded question in a survey?

Accepted Answer

Do you agree that the wasteful city council should be replaced to save taxpayer money?

Question 4

A study finds that people who eat more vegetables tend to have lower rates of heart disease. Which of the following best describes the relationship found?

Accepted Answer

Correlation: Eating vegetables is associated with lower heart disease, but causation is not established.

Question 5

Which of the following is an example of quantitative discrete data?

Accepted Answer

The number of books on a shelf.

Question 6

A researcher collects data on the number of siblings each student in a class has. What is the level of measurement for this data?

Accepted Answer

Ratio

Question 7

Which sampling method is being used if a researcher selects every 10th person entering a hospital for a survey?

Accepted Answer

Systematic sampling

Question 8

A study follows a group of patients over 10 years to observe the development of a disease. What type of study is this?

Accepted Answer

Prospective (longitudinal) study

Question 9

Which of the following best describes a double-blind experiment?

Accepted Answer

Neither the subjects nor the data collectors know which subjects receive the treatment.

Question 10

A researcher wants to estimate the percentage of left-handed students at a university. She surveys only the students in her statistics class. What is the main problem with this sampling method?

Accepted Answer

It is a convenience sample and may not represent the entire university.

Question 11

If a data set consists of the following values: 2, 4, 6, 8, what is the percentage of values greater than 4?

Accepted Answer

$$\frac{2}{4} 	imes 100 = 50\%$$

Question 12

Which of the following is an example of data measured at the ordinal level?

Accepted Answer

The star ratings (1 to 5 stars) given to a movie.

Question 13

A researcher wants to study the effect of a new medication. She randomly assigns patients to two groups: one receives the medication, the other receives a placebo. What type of study is this?

Accepted Answer

Experimental study

Question 14

Which of the following is a parameter?

Accepted Answer

The average GPA of all students at a college.

Question 15

A researcher divides a city into neighborhoods and randomly selects several neighborhoods. She then surveys all residents in those selected neighborhoods. What sampling method is this?

Accepted Answer

Cluster sampling

Question 16

Which of the following statements about interval and ratio levels of measurement is correct?

Accepted Answer

Ratio data allows for meaningful ratios and has a natural zero; interval data does not have a natural zero.

Question 17

A poll asks, 'Do you support spending $10 million to improve local parks?' What type of bias might this question introduce?

Accepted Answer

Loaded question bias

Question 18

If 23,000 students attend a college and 54% are female, how many female students are there?

Accepted Answer

$$23,000 	imes 0.54 = 12,420$$

Question 19

A researcher wants to ensure that her sample reflects the age distribution of the population. She divides the population into age groups and randomly selects a proportional number from each group. What sampling method is this?

Accepted Answer

Stratified sampling

Question 20

Which of the following scenarios best illustrates confounding in an experiment?

Accepted Answer

A restaurant raises prices and, at the same time, road construction begins nearby, making it unclear which factor caused a drop in customers.

Chapter 1: Introduction to Statistics – Structured Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard