AP Stats Chapter 3 Review

• A residual plot is not an appropriate means for evaluating a linear model.

• The curved pattern in the residual plot suggests that there is no association between the

  weight and height of basketball players.

• The curved pattern in the residual plot suggests that the linear model is not appropriate.

• There are not enough data points to draw any conclusions from the residual plot.

• The linear model is appropriate, because there are approximately the same number of

  points above and below the horizontal line in the residual plot.

A high-school administrator who is concerned about the amount of sleep the students in his district are getting selects a random sample of 14 seniors in his district and asks them how many hours of sleep they get on a typical school night. He then uses school records to determine the most recent grade-point average (GPA) for each student. Here is the regression output. Assume the conditions for inference are met. Predict the GPA for a senior in this district who gets 8 hours of sleep on a typical school night.

• 3.46

• 4.09

• 0.50

• 2.65

• 3.28

3)

• A

• B

• C

• D

Estimate the correlation coefficient.

• r = -0.8

• r = -0.5

• r = 0.5

• r = 0.8

The scatter plot in the figure below shows the GPA of the students of a class versus their commute time. Which of the following statements is true?

• The relationship between GPA and commute time is moderate positive linear.

• The relationship between GPA and commute time is moderate negative linear.

• The scatter plot does not have any outliers.

What is the correlation?

• Negative correlation

• No correlation

• Positive correlation

• Cannot be determined

What type of association does this graph have?

• positive 

• negative

• none

• all of the above

A correlation shows that two things are

• related

• causing each other

• unrelated

• causation

After performing analyses on a set of data, Mrs. Schoeneck examined the scatter plot of the residual values for each analysis. Which scatter plot indicated the best linear fit for the data?

• A

• B

• C

Shown is a residual plot. Would a linear regression model of the data be most appropriate?

• YES

• NO