Directions: Read carefully. These questions pertain to correlations and correlation coefficients.

Choose the scatter plot which could possibly have the given r -value:
 1. r = 0.50 A B C D E F

 2. r = 0 A B C D E F

 3. r = -0.85 A B C D E F

 4. r = 0.92 A B C D E F

 5. r = 1 A B C D E F

 6. r = -0.48 A B C D E F

7.  What does it mean to say that data has a strong negative correlation?
 Choose: There is no relationship at all between the variables. More than half of the variables have a negative value. There is a negative cause and effect relationship. A linear model with a negative slope is appropriate.

8.  Which of the following correlation coefficients represents the strongest linear relationship?
 Choose: 0.79 0.36 -0.12 -0.87

9.  The relationship between the number of widgets in a package (x-axis) and the length of the package (y-axis), in inches, is given in the table at the right. The linear correlation coefficient for this relationship is:
Choose:
 1 -1 0.5 0
 Number of Widgets Length of Package (in.) 3 9.00 4 9.25 5 9.50 6 9.75

10.  Which calculator output shows the strongest linear relationship between x and y?
Choose:
 LinReg y = ax + b a = 58.135 b = 7.348 r = 0.843 LinReg y = a + bx a = 0.702 b = 24.286 r = 0.8145 LinReg y = ax + b a = 0.952 b = 3.45 r = 0.633 LinReg y = ax + b a = 22.567 b = -4.332 r = 0.894

11.  Which value of r represents data with a strong positive linear correlation betweeen two variables?
Choose:
 0.91 0.42 1.03 0.01

12.  The table at the right shows the average target training heart rates, by age, according to the American Heart Association. Which value represents the linear correlation coefficient between a person's age, in years, and that person's average target training heart rate, in beats per minute (bpm)? (Round to four decimal places with Age on x-axis and Heart Rate on y-axis.)
Choose:
 -0.6652 1.3231 -0.9996 0.9993
 Age (years) Average Target Heart Rate (bpm) 20 135 30 129 40 122 50 115 60 108 70 102