The yield of a chemical process is being studied. The two factors of interest are temperature and pressure. Three levels of each factor are selected; however, only nine runs can be made in one day. The experimenter runs a complete replicate of the design on each day. The data are shown in the following table. Analyze the data, assuming that the days are blocks.

Day 1 Pressure Day 2 Pressure Temperature 250 260 270 250 260 270 Low 86.3 84.0 85.8 86.1 85.2 87.3 Medium 88.5 87.3 89.0 89.4 89.9 90.3 High 89.1 90.2 91.3 91.7 93.2 93.7