问题如下：
Suppose that you deleted several of the observations that had small residual values. If you re-estimated the regression equation using this reduced sample, what would likely happen to the standard error of the estimate and the R-squared?
选项：
Standard Error of the Estimate
R-Squared
A. DecreaseDecrease
B. DecreaseIncrease
C. IncreaseDecrease
解释：
c is correct.
Deleting observations with small residuals will degrade the strength of the regression, resulting in an increase in the standard error and a decrease in R-squared.
老师请解释一下 R squared 的影响
