7. A blood sample was taken from 100 smokers between the ages of 45 and 65 and then cholesterol levels were recorded. The cholesterol values were as follows: 199 240 255 181 178 181 287 219 218 256 267 209 199 382 246 234 179 286 273 296 289 224 221 225 257 186 243 194 235 274 298 230 248 166 171 240 288 198 239 255 198 175 249 189 232 192 277 231 211 241 251 238 147 211 196 202 231 240 223 268 201 239 213 189 185 195 279 231 203 259 230 164 212 217 238 190 199 243 163 134 219 205 186 214 187 216 234 290 199 228 235 221 266 244 199 263 301 284 217 223 a. Determine the range. b. Determine the number of class intervals if 20 scores are to be grouped into each interval. c. Set the class limits for each interval if the lower limit of the lowest class interval is 130. d. Tabulate and tally the scores for each interval, and record the frequency and the cumulative frequency. + Relative