data for a simple random sample of 100 people without cardiovascular disease at enrolment. At enrollment, total cholesterol was measured. Total cholesterol levels were tracked for 10 years to determine if they predicted CHD events. One cohort member per row. Variables in this data include: ?Part_id: Participant ID (1 to 100) Gender: Subject gender ("M" or "F") ?Age: Subject age (years) ?Chol: Total cholesterol level (mg/dL) at enrollment ?CHD: Indicator of CHD event (1= CHD event, 0 = no CHD event) at year 10 Investigators want to compare the average total cholesterol values (Chol) of people with and without CHD events to see if they differ. A) show and draw the null and alternative hypotheses for this situation. Hypothesis test assumptions. Assumptions met? Briefly explain. Should cholesterol readings be regularly distributed? Is this problem normally distributed? Briefly explain. B) Give each group's average cholesterol. Hypothesis test statistics. Show some intermediate steps and relevant computer output. Calculate p. Specify degrees of freedom. C) interpret in context the Non-statisticians should use the p-value as a probability. Do the two populations' average total cholesterol values match? Any conclusions?

BMI2 Chol Age P ID Trt Smoke LDL HDL 0 0 2.49 316 244 41 58 0 2.56 269 175 47 53 2.66 222 149 58 51 2.71 300 240 40 56 2.69 288 198 53 42 2.56 234 164 42 54 2.59 303 215 40 46 3.05 268 197 35 60 0 1.87 225 160 37 50 2.45 254 171 63 57 0 2.44 325 254 41 55 -- 289 181 48 56 2.60 259 185 37 45 2.82 205 141 40 55 3.07 351 278 50 51 2.92 270 186 59 55 - o . . - 0 - 2.49 195 130 28 50 3.04 244 171 46 47 3.03 378 297 53 40 2.35 265 171 73 55 2.66 283 202 49 51 2.77 277 219 36 54 2.45 276 193 52 56 3.02 340 268 50 41 2.64 211 145 51 56 2 . 270 195 56 42 2.4 268 193 36 35 2.52 299 225 51 57 -- .75 276 195 58 2.46 229 165 2.9 240 169 44 2.68 285 207 46 2.15 293 208 63 59 2.63 257 187 42 56 2.41 253 154 39 48 2.7 329 259 40 44 180 29 44 --- 2.7 240 2.65 237 167 50 2.87 305 207 63 35 2.27 283 214 49 58 2.35 268 185 43 56 2.47 275 170 73 56 2.46 297 225 47 41 2.57 290 202 35 58 2.42 290 204 40 51 2.69 267 201 38 59 3.04 261 187 58 37 3.23 246 167 44 58 3.05 265 176 47 54 2.64 293 205 45 44 o-- 2.53 365 299 36 36 2.65 283 223 35 50 2.60 261 189 43 53 2.78 260 191 38 46 2.69 287 225 31 50 3.26 257 186 44 53 - - - - - . . . - 2. 273 181 40 56 .38 280 222 40 41 2.92 317 220 53 42 2.51 211 122 51 48 2.68 202 132 37 2.39 283 210 36 2.99 238 152 52 2.65 261 173 59 2.5 197 116 48 2.63 211 118 43 38 2.53 298 219 56 2.6 283 199 49 2.38 178 114 58 2.43 285 204 45 o---- 2.81 285 216 56 2.65 262 183 38 2.78 272 185 48 2.34 239 168 52 2.58 376 314 48 2.84 246 183 37 58 2.69 387 304 39 41 ----o- - - 2.47 226 152 39 49 2.54 280 186 45 58 2.51 228 137 58 47 2.65 285 203 36 43 2.88 299 209 38 37 2.49 191 94 36 54 2.55 205 130 40 2.77 338 251 O-.- - - 2.57 249 175 44 2.53 332 252 43 2.93 321 255 39 2.42 270 186 45 2.76 322 243 39 O - - - 2.51 189 129 47 2.95 268 172 57 2.39 285 217 46 2.84 265 199 40 -- 2.69 195 106 2.33 330 257 - -O - 2.82 308 220 2.36 190 140 2.15 273 173 2 .73 424 346 1 2.27 266 190 102 2.71 178 98 59 47 0 3.27 290 181 61 45 103 38 104 2.7 261 171 71 10 2.34 204 138 49 49 106 2.72 247 159 50 107 2.85 258 177 108 2.82 278 217 92 109 3.02 171