Chapter 2.4, Problem 39E

CHOLESTEROL LEVELS Mr. Cross, Mr. Jones, and Mr. Smith all suffer from coronary heart disease. As part of their treatment, they were put on special low-cholesterol diets: Cross on Diet I, Jones on Diet II, and Smith on Diet III. Progressive records of each patient's cholesterol level were kept. At the beginning of the first, second, third, and fourth months, the cholesterol levels of the three patients were as follows:

Cross:	$220$, $215$, $210$, and $205$
Jones:	$220$, $210$, $200$, and $195$
Smith:	$215$, $205$, $195$, and $190$

a. Represent this information using a $3\times 4$ matrix $A$ .Find $a_{24}$ and explain its meaning.

b. Represent this information using a $4\times 3$ matrix $B$ .Find $a_{32}$ and explain its meaning.