Table 6.10 refers to a study that randomly assigned subjects to a control group or a treatment group. Daily during the study, treatment subjects ate cereal containing psyllium. The purpose of the study was to analyze whether this resulted in lowering LDL cholesterol. Using a frequentist or Bayesian approach, model the ending cholesterol level as a function of treatment, treating the beginning level

(a) as a covariate with sensible scores and

(b) as a categorical control variable. In each case, analyze the treatment effect. Compare results and interpret.

Table 6.10 Data for Exercise 6.16 on cholesterol study.

Ending LDL Cholesterol Level Control Treatment Beginning ≤3.4 3.4–4.1 4.1–4.9 >4.9 ≤3.4 3.4–4.1 4.1–4.9 >4.9

≤3.4 18 8 0 0 21 4 2 0 3.4–4.1 16 30 13 2 17 25 6 0 4.1–4.9 0 14 28 7 11 35 36 6

>4.9 0 2 15 22 1 5 14 12 Source: Dr. Sallee Anderson, Kellogg Co.