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 (Temperature, Porosity) data follow: (1100, 30.8), (1200, 19.2), (1300, 6.0), (1100, 13.5), (1500, 11.4), (1200, 7.7), (1300, 3.6).

1). For the model Porosity = a + (b * Temperature), the values for a and b derived from a least squares analysis of the (Temperaure, Porosity) data points given aboveare closest to:

2). For the least squares model developed in Question Nineteen (19), the value of the correlation coefficient is closest to