Lower Your Cholesterol Researchers Francisco Fuentes and his colleagues wanted to

Chapter 13, Problem 22

(choose chapter or problem)

Lower Your Cholesterol Researchers Francisco Fuentes and his colleagues wanted to determine the most effective diet for reducing LDL cholesterol, the so-called bad cholesterol, among three diets: (1) a saturated-fat diet, (2) the Mediterranean diet, and (3) the U.S. National Cholesterol Education Program or NCEP-1 Diet. The participants in the study were shown to have the same levels of LDL cholesterol before the study. Participants were randomly assigned to one of the three treatment groups. Individuals in group 1 received the saturated-fat diet, which is 15% protein, 47% carbohydrates, and 38% fat (20% saturated fat, 12% monounsaturated fat, and 6% polyunsaturated fat). Individuals in group 2 received the Mediterranean diet, which is 47% carbohydrates, and 38% fat (610% saturated fat, 22% monounsaturated fat, and 6% polyunsaturated fat). Individuals in group 3 received the NCEP-1 Diet (610% saturated fat, 12% monounsaturated fat, and 6% polyunsaturated fat). After 28 days, their LDL cholesterol levels were recorded. The data in the following table are based on this study. Saturated Fat Mediterranean NCEP-1 245 218 56 131 125 184 123 173 78 125 100 116 166 223 101 160 140 144 104 177 158 130 151 101 196 193 145 83 138 135 300 224 118 263 268 144 140 149 145 150 75 130 240 211 71 (a) State the null and alternative hypotheses.(b) Verify that the requirements to use the one-way ANOVAprocedure are satisfied. Normal probability plots indicatethat the sample data come from normal populations.(c) Are the mean LDL cholesterol levels different at thea = 0.05 level of significance?(d) Draw boxplots of the LDL cholesterol levels for the threegroups to support the analytic results obtained in part (c).