9. Which of the following statements regarding regression and
correlation are true? (There may be more than one correct
answer.)
a) A value of the linear correlation, r, near -1 means the data
is tightly bundled around a line, and predictions within the scope
of data are very reliable.
b) When the slope of a linear regression equation is near 0,
then the linear correlation between the two variables must also be
near 0.
c) The average error between the actual values and the predicted
values of a least squares line will always be near zero.
d) A positive correlation between two variables implies the
slope of the regression line will also be positive.