Question 1

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

Accepted Answer

Neither the participants nor the experimenters know who is receiving the treatment.

Question 2

A researcher wants to study the effect of a new drug. She randomly assigns participants to either the drug group or the placebo group. What type of sampling method is this?

Accepted Answer

Simple random sampling

Question 3

Given the following data set: 2, 4, 4, 6, 8, what is the median?

Accepted Answer

$$4$$

Question 4

Which formula correctly calculates the $$z-$$score for a value $$X in a $$population with mean $$\mu$$ and standard deviation $$\sigma$$?

Accepted Answer

$$z = \frac{X - \mu}{\sigma}$$

Question 5

A histogram is best used to display which type of data?

Accepted Answer

Continuous numerical data

Question 6

If a distribution is skewed to the right, which of the following is most likely true?

Accepted Answer

The mean is greater than the median.

Question 7

Which of the following best describes the Empirical Rule?

Accepted Answer

About 68% of data falls within one standard deviation, 95% within two, and 99.7% within three standard deviations of the mean.

Question 8

Which of the following is a lurking variable?

Accepted Answer

A variable not included in the study that affects the relationship between the explanatory and response variables.

Question 9

A scatterplot shows a strong positive linear relationship between two variables. What is the most likely value for the correlation coefficient $$r$$?

Accepted Answer

$$0.85$$

Question 10

Which of the following best explains Simpson's Paradox?

Accepted Answer

A trend appears in several groups of data but reverses when the groups are combined.

Question 11

A boxplot is most useful for identifying which of the following?

Accepted Answer

Outliers in a data set

Question 12

Which sampling method divides the population into groups and randomly selects some groups to sample all members within them?

Accepted Answer

Cluster sampling

Question 13

If the mean of a data set is 50 and the standard deviation is 5, what is the $$z-$$score for a value of 60?

Accepted Answer

$$z = 2$$

Question 14

Which of the following is NOT a measure of central tendency?

Accepted Answer

Standard deviation

Question 15

A researcher uses a bar graph to display the number of students in different majors. What type of variable is being displayed?

Accepted Answer

Categorical variable

Question 16

Which of the following best describes an explanatory variable?

Accepted Answer

A variable that is manipulated to observe its effect on the response variable.

Question 17

Which of the following is the correct formula for the least squares regression line?

Accepted Answer

$$y = a + bx$$

Question 18

In a real-life scenario, when is the median preferred over the mean as a measure of center?

Accepted Answer

When the data set contains outliers or is skewed.

Question 19

Which of the following is a characteristic of a normal distribution?

Accepted Answer

It is symmetric and bell-shaped.

Question 20

A study finds a correlation coefficient $$r = -0.92$$ between hours of TV watched and exam scores. What does this indicate?

Accepted Answer

There is a strong negative linear relationship between hours of TV watched and exam scores.

Statistics Review Chapters 1-4: Essential Concepts and Applications

Guida di studio - Domande di pratica

Study guide - Flashcard