In an online report, Medscape Today News reported that anesthesiologists earned a mean income of $309,000 in 2011 (February 22, 2013). Compensation covers salary, bonus, and profit-sharing contributions. Are there regional differences in anesthesiologist’s compensation east of the Mississippi River? Suppose that in a follow-up study of 14 anesthesiologists from east of the Mississippi River and 14 anesthesiologists from west of the Mississippi River yields the following results (in $1,000's):

East of Mississippi West of Mississippi

268 ...........380

274 ...........364

282 ...........300

291 ...........364

237 ...........339

249 ...........271

234 ...........322

235 ...........403

261 ...........384

272 ...........238

330 ...........342

371 ...........300

245 ...........244

301 ...........271

a. Develop a point estimate of the difference between the population incomes for anesthesiologists from east of the Mississippi River and west of the Mississippi River.

b. Develop a 99% confidence interval estimate of the difference between the population incomes for anesthesiologists from east of the Mississippi River and west of the Mississippi River.

c. Do your results suggest that annual income of anesthesiologists from east of the Mississippi River is at least as large as annual incomes of anesthesiologists from west of the Mississippi River?