An article in the journal of the american ceramic society, “rapid hot-pressing of ultrafine psz powders” (1991, vol. 74, pp. 1547–1553) considered the microstructure of the ultrafine powder of partially stabilized zirconia as a function of temperature. the data are shown below: x = temperature (°c) 1100 1200 1300 1100 1500 1200 1300 y = porosity (%) 30.8 19.2 6 13.5 11.4 7.7 3.6 (a) fit the simple linear regression model using the method of least squares. find the least squares estimates of the intercept and slope in the simple linear regression model.