Using the labeling as in Table 9.7, write the contrasts that would correspond to the following statements: (a) The difference between 4- and 6-cylinder engines is the same for the STANDARD oil as it...

Using the labeling as in Table 9.7, write the contrasts that would correspond to the following statements:

(a) The difference between 4- and 6-cylinder engines is the same for the STANDARD oil as it is for the GASMISER oil.

(b) The difference between STANDARD and GASMISER oil is the same for 4- cylinder engines as it is for 6-cylinder engines.

(c) There is no difference between 4- and 6-cylinder engines, averaged over all three types of oil.