A researcher is trying to determine if income(X1) or number of friends (X2) is more important in determining personal happiness (Y). Which of the following would be the most profitable course of action?
a. Examine the standardized partial slopes of X1 and X2 on Y.
b. Examine the unstandardized partial slopes of X1 and X2 on Y.
c. Compute the partial correlation coefficient for X1 and X2 controlling for Y.
d. Examine the partial slope of Y on each independent separately.