Select all statements that are true of the least-squares regression line. C] It assumes a linear relationship between the explanatory and the response variable. C] It can be used to predict the mean response of the explanatory variable. C] R-squared is the portion of sample variance in the yvariable that can be explained by variation in the xvariable. C] R-squared is the portion of sample variance in the explanatory variable that can be explained by variation in the response variable