Checking only whether the sum of residuals is zero is not sufficient to determine if a linear regression model is appropriate. While the sum of residuals will always equal zero, one should also examine the residual plot for any patterns, as a pattern would indicate that a linear model is not appropriate for the data.

1. Do you agree with the following statement? "Checking whether the sum of residuals is zero is
sufficient to conclude that a linear regression model is appropriate."
A. No, the sum of residuals will always add to zero. One should also check the residual plot. If
there is a pattern in the residual plot, it indicates that a linear regression model is NOT
appropriate.
B. Yes. In fact, examining only the scatterplot of Y vs. X is sufficient to conclude that a linear
regression model is appropriate.
C. Yes, the sum of residuals equating to zero confirms appropriateness of a linear regression
model.
D. No, the sum of residuals will never add to zero. It is either +1 or ?1.
Solution
C. No, the sum of residuals will always add to zero. One should also check the
residual plot. If there is a pattern in the residual plot, it indicates that a linear regression model is
NOT appropriate.