AP Stats - Bivariate Data

True or False: Causation can be determined if a very strong correlation coefficient (r) is found.

• True

• False

True or False: It is risky to use the least-squares regression equation to make a prediction that is outside the range of values in the observed values.

• True

• False

True or False: If r = 0.9, then the 90% of variation in the response variable is explained by the predictor variable in the least-squares regression line.

• True

• False

True or False: If the correlation coefficient (r) is negative, then the coefficient of determination (r^2) will be positive.

• True

• False

A researcher performs an experiment to find if there is a correlation between amount of time spent a day on a computer and the need for corrective lenses. There is a correlation coefficient of 0.73 found. Which of the following is true?

• 53.29% of the variance in the need for corrective lenses is explained by the relationship between the need for corrective lenses and the amount of time a day spent of a computer.
• The strength of the linear relationship between the need for corrective lenses and the amount of time a day spent on a computer is 0.5329.
• 73.00% of the variance in the need for corrective lenses is explained by the relationship between the need for corrective lenses and
• The strength of the linear relationship between the need for corrective lenses and the amount of time a day spent on a computer is 0.8544.

Which of the following statistics show how much variance there is between y–values and x–values?

• Coefficient of Determination (r-squared)

• Slope of the Regression Line

• Standard Deviation

• Variance

Below are the grades of a college student for the year, along how much work the class required. What is the coefficient of determination (r-squared)?

• –0.0800
• –0.0320
• 0.0064
• 0.2100

Which of the following is the least–square regression line for this data?

• y = 3.85 – 0.01x
• y = 4.09 – 0.32x
• y = 6.30 – 0.59x
• y = 8.18 – 0.64x

Tags

CCSS.HSA.CED.A.2

CCSS.HSS.ID.B.6

CCSS.HSS.ID.C.7

Victoria found the least squares regression line for a set of data and then graphed a residual plot. She found that all the residuals were above 0. Which of the following is true?

• Every point must have been above the regression line.
• The slope of the regression line must be 0
• The residuals are all outliers
• This is not possible and must be the result of an error on Victoria's part.

An influential observation is most often

• larger than most other values in the y–direction
• larger than most other values in the x–direction
• not an outlier
• an outlier in the x direction

Tags

CCSS.HSS.ID.A.3