Write down the X matrix for (3.75) in the starch experiment. Kodlin (1951) reported an experiment that compared two substances for lowering blood pressure, denoted as substances A and B. Two groups...

Write down the X matrix for (3.75) in the starch experiment.

Kodlin (1951) reported an experiment that compared two substances for lowering blood pressure, denoted as substances A and B. Two groups of animals

are randomized to the two substances and a decrease in pressure is recorded.

The initial pressure is also recorded. The data for the blood pressure experiment appear in Table 3.49. Compare the two substances by accounting for

possible effect of the initial pressure on the decrease in pressure. Discuss the

results of the ANCOVA analysis and compare them with those obtained by

ignoring the potential effect of initial pressure.