Question 1

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

Accepted Answer

A sample is a subset of a population.

Question 2

A researcher wants to study the average blood pressure of adults in a city. She randomly selects 200 adults from the city and records their blood pressure. What is the sample in this scenario?

Accepted Answer

The 200 adults selected and measured.

Question 3

Which level of measurement is appropriate for the following variable: temperature measured in degrees Celsius?

Accepted Answer

Interval

Question 4

A survey asks respondents to rate their satisfaction as 'unsatisfied', 'neutral', or 'satisfied'. What is the level of measurement for this variable?

Accepted Answer

Ordinal

Question 5

Which of the following is an example of a variable measured at the ratio level?

Accepted Answer

Height in centimeters

Question 6

A medical study divides patients into two groups: one receives a new drug, and the other receives a placebo. What is the placebo group called?

Accepted Answer

Control group

Question 7

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

Accepted Answer

Neither the subjects nor the experimenters know which group receives the treatment.

Question 8

Given the frequency distribution below, what is the cumulative frequency for the class interval 60-69?

Class Interval: 40-49, 50-59, 60-69, 70-79
Frequency: 5, 8, 12, 10

Accepted Answer

$$25$$

Question 9

Which of the following graphs is most appropriate for displaying the distribution of a categorical variable such as favorite color?

Accepted Answer

Pie chart

Question 10

A researcher collects the following data on the number of siblings for each student in a class: 0, 1, 2, 2, 3, 4, 4, 5. What is the median number of siblings?

Accepted Answer

$$2.5$$

Question 11

Which of the following is a real-world example of using a stratified sampling method?

Accepted Answer

Dividing a hospital's patients into age groups and randomly sampling from each group.

Question 12

A frequency distribution table shows the following data for test scores:

Score: 50, 60, 70, 80, 90
Frequency: 2, 5, 8, 3, 2

What is the relative frequency for the score 70?

Accepted Answer

$$\frac{8}{20}$$

Question 13

Which of the following best describes the purpose of a stem-and-leaf plot?

Accepted Answer

To display the distribution of a quantitative variable while preserving the original data values.

Question 14

A researcher wants to compare the mean income of two cities. Which statistical graph would be most appropriate?

Accepted Answer

Boxplot

Question 15

Which of the following is NOT a characteristic of the normal distribution?

Accepted Answer

It is skewed to the right.

Question 16

A study finds that the correlation coefficient between hours studied and exam score is $$r = 0.85. $$What does this indicate?

Accepted Answer

There is a strong positive linear relationship between hours studied and exam score.

Question 17

Which of the following is the formula for calculating the mean of a data set?

Accepted Answer

$$\mu = \frac{\sum x_i}{N}$$

Question 18

A researcher wants to determine 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 19

Which of the following is a real-world example of a confounding variable in a medical study?

Accepted Answer

A variable that affects both the treatment and the outcome, such as age in a study of exercise and heart health.

Question 20

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

Accepted Answer

Descriptive statistics summarize data; inferential statistics make predictions or generalizations about a population.

Practice Test 1 Study Notes: Introduction to Statistics & Exploring Data (Chapters 1 & 2)

스터디 가이드 - 연습 문제

학습 가이드 - 플래시카드