Example 12.6 presented the residuals from a simple linear regression of moisture content y on filtration rate x.
a. Plot the residuals against x. Does the resulting plot suggest that a straight-line regression function is a reasonable choice of model? Explain your reasoning.
b. Using s 5 .665, compute the values of the standardized residuals. Is ei* < ei's for i = 1,..., n, or are the ei* 's not close to being proportional to the ei's?
c. Plot the standardized residuals against x. Does the plot differ significantly in general appearance from the plot of part (a)?