4.Which of the following statements about linear regression analysis is most accurate?

A)   The coefficient of determination is defined as the strength of the linear relationship between two variables.

B)   A perfectly negative correlation can be depicted by a correlation coefficient of +1.

C)   When there is a strong relationship between two variables we can conclude that a change in one will cause a change in the other.

D)   An assumption of linear regression is that the residuals are independently distributed.

[此贴子已经被作者于2008-4-1 13:24:58编辑过]

The correct answer was D)

A perfectly negative correlation can be depicted by a correlation coefficient of -1. Even when there is a strong relationship between two variables, we cannot conclude that a causal relationship exists. The coefficient of determination is defined as the percentage of total variation in the dependent variable explained by the independent variable.