Refer to Exercise 11-11, which presented data on chloride concentration y and roadway area x (a) What proportion of the total variability in chloride concentration is accounted for by the regression...

Refer to Exercise 11-11, which presented data on chloride concentration y and roadway area x
(a) What proportion of the total variability in chloride concentration is accounted for by the regression model?
(b) Plot the residuals versus and versus x. Interpret these plots.
(c) Prepare a normal probability plot of the residuals. Does the normality assumption appear to be satisfied?