Question

1. A crossover study was conducted to investigate whether oat bran cereal helps to lower serum cholesterol in hypercholesterolemic males. Fourteen such individuals were randomly placed on a diet that included either oat bran or corn flakes; after two weeks, their low-density lipoprotein (LDL) cholesterol levels were recorded. Each man was then switched to the alternative diet. After a second two-week period, the LDL cholesterol level of each individual was again recorded. The data from this study are shown below: Subject Corn flakes Oat bran 1 4.61 3.84 2 6.42 5.57 3 5.4 5.85 4 4.54 4.8 5 3.98 3.68 6 3.82 2.96 7 5.01 4.41 8 4.34 3.72 9 3.8 3.49 10 4.56 3.84 11 5.35 5.26 12 3.89 3.73 13 2.25 1.84 14 4.24 4.14 a. Are the two samples of data paired or independent? b. What are the appropriate null and alternative hypotheses for a one-sided test? c. Conduct the test at the 0.05 significance level. What is the p-value? d. What do you conclude?

Answer 1