3. Subjects in this data are randomized into calcium treatment and placebo. a. What study design is that? And why do we need a placebo group? b. how would you design the study to better exclude the influence of age, gender and race? c. How would you design a study to examine whether calcium intake relates to cardiovascular disease in the general population? Give at least two study designs. A B C D E F G H K M 1 Treatment Begin End Decrease Gender Age HeartRate Temperaturos hospital.id insurer race bed.size Calcium 107 100 7 M 33 69 97 17 Calcium 110 114 4 M 32 72 98.8 17 Calcium 123 105 18 M 42 68 96.2 17 NNAWNG 5 Calcium 129 112 17 F 33 75 97.8 17 6 Calcium 112 115 - 3 F 26 68 98.8 17 7 Calcium 111 116 -5 M 37 79 101.3 17 8 Calcium 107 106 1 F 32 71 7.8 17 Calcium 112 102 10 F 45 73 97.4 17 10 Calcium 136 125 11 F 31 77 99.2 17 11 102 104 -2 M 49 81 99.2 17 W W W N W A N H H W H N N W N N W HAN 12 Calcium 106 100 7 M 40 69 97.5 17 13 Calcium 112 114 4 F 45 70 97.7 17 o o o o o o o o O O 14 Calcium 123 105 18 F 49 71 98.3 17 15 130 112 17 37 74 98.8 17 16 Calcium 111 115 -3 F 47 79 98.5 17 17 Calcium 111 116 -5 M 34 73 97.3 17 18 Calcium 108 106 1 F 41 71 98.9 17 19 Calcium 112 102 10 M 33 77 18.6 27 20 Calcium 136 125 11 F 38 70 99.2 27 21 Calcium 102 104 -2 F 31 69 97.9 27 Placebo 123 124 -1 F 41 67 97.1 57 23 Placebo 109 97 12 F 45 67 97 57 24 Placebo 112 113 -1 F 36 74 98.9 57 25 Placebo 102 105 -3 M 35 77 99 57 AN JWHANHWHYWONGWNANPNEWNWPPNPPPWNNPP Placebo 98 95 3 F 28 76 97.9 27 Placebo 114 119 -5 M 25 79 BE 28 Placebo 119 114 5 M 30 76 37 Placebo 112 114 2 M 41 61 7.6 o o o o o o o o o o o o o o o O 0 0 0 30 Placebo 110 121 11 M 37 84 99 31 Placebo 117 118 -1 F 37 67 37.8 N N N N N N N N N N N N N N N N N N N N N NAA. 32 Placebo 130 133 -3 F 34 73 97.9 Placebo 123 124 -1 F 34 81 100 34 Placebo 107 97 12 M 50 68 97.1 w w w w w w w w w w w w w w w w w w* 35 Placebo 111 113 -1 M 48 76 98.9 5 Placebo 101 105 -3 M 34 80 98.6 37 Placebo 98 95 3 F 36 68 977 38 Placebo 114 119 -5 F 21 70 38.3 39 Placebo 119 114 5 M 23 79 98.9 0 Placebo 112 114 2 F 42 76 99.4 41 Placebo 109 121 11 F 33 75 98.6 42 Placebo 118 118 -1 M 37 73 97.2 Placebo 130 133 -3 M 33 72 98