AP Stats Unit 2 Practice

What is the purpose of a scatterplot?

• To display the relationship between two quantitative variables

• To calculate the correlation between two variables

• To determine the equation of a least-squares regression line

• To identify outliers in a dataset

Which of the following statements about correlation is true?

• Correlation does not imply causation

• Correlation is resistant to outliers

• Correlation can only describe linear relationships

• Correlation is influenced by the units of measurement

What is the equation of a least-squares regression line?

• ŷ = a + bx

• y = mx + b

• y = a + bx

• ŷ = mx + b

What does the coefficient of determination (r^2) represent?

• The proportion of variation in the response variable explained by the regression line

• The average size of the residuals in a regression model

• The slope of the regression line

• The y-intercept of the regression line

What is the purpose of a residual plot?

• To assess how well a regression line fits the data

• To calculate the standard deviation of the residuals

• To identify outliers in a dataset

• To determine the equation of a least-squares regression line

What is an outlier in the context of regression?

• An observation that lies outside the overall pattern of the other observations

• A point that is extreme in the y direction of a scatterplot

• A point that is extreme in the x direction of a scatterplot

• An observation that has a large residual

What makes a point influential in regression?

• Being extreme in the x direction of a scatterplot

• Having a large residual

• Being extreme in the y direction of a scatterplot

• Having a high correlation coefficient

Identify the term being interpreted below:"The actual height(y) is typically about 2.6 in away from the height predicted by the LSRL given weight(x)"

• slope

• y-intercept

• standard deviation of the residuals (S)

• coefficient of determination (r^2)

Identify the term being interpreted below: "About 45% of the variability of height (y) can be accounted for by the LSRL for weight (x)."

• slope

• y-intercept

• standard deviation of the residuals (S)

• coefficient of determination (r^2)

Identify the term being interpreted below:"With each additional pound of weight (x) the predicted (y) increases by 5"

• slope

• y-intercept

• standard deviation of the residuals (S)

• coefficient of determination (r^2)