Dietary study. Clinical investigators recruited health adults with moderately high cholesterol for a clinical trial to compare three diets: A, B, and Control. The 30 participants were randomly assigned to one of the three diets by age group (<50 or 50+) and the intervention lasted 6 weeks. The primary endpoint was change in cholesterol from baseline to study end. The data from the study are provided below:

ID treatment age group Change in cholesterol

101 A <50 -44

102 A <50 -50

103 A <50 -77

104 A <50 -64

105 A <50 -48

106 A 50+ -71

107 A 50+ -27

108 A 50+ -31

109 A 50+ -44

110 A 50+ -56

111 A <50 -43

112 A <50 -52

113 A <50 -70

114 A <50 -46

115 A <50 -42

116 A 50+ -79

117 A 50+ -82

118 A 50+ -87

119 A 50+ -35

120 A 50+ -77

121 control <50 -20

122 control <50 -7

123 control <50 1

124 control <50 -27

125 control <50 3

126 control 50+-3

127 control 50+ 24

128 control 50+ 4

129 control 50+ -25

130 control 50+ 13

a.What type of experimental design is this? Why?

b.What are the possible tests of hypothesis that you can make?

c.Provide a table of descriptive statistics for the trial.

d.Perform the analysis and provide your ANOVA table.

e.What are your conclusions? How do you justify them?