8. Consider the data for the product array design for the elastometric connec-

tor shown in Figure 12.4.

(a) Calculate the mean pull-o force and log variance of the pull-o force across the noise array for each run in the control-factor array.

(b) Analyze the data using the location-dispersion modeling method.

(c) Do you nd the same optimal levels of the control factors as identied in Section 12.4.2?

(d) Is any information lost when analyzing this data using location-dispersion modeling?

9. Reconsider the data from the injection molding experiment in Table 12.12.

(a) Fit the model y = 0 +AXA +BXB +ABXAXB in the adjustment factors using the method of least squares.

(b) Simultaneously estimate the variance of the residuals at each level of the dispersion factor, C, and compute the weighted least squares estimates of the coecients in the model in

(a) using proc mixed as shown in Section 12.6.1.