I really dont understand this question

Question 6: (from chapter 10) A neighborhood home owners association suspects that the recent appraisal values of the houses in the neighborhood conducted by the county government for taxation purposes is too high. It hired a private company to appraise the values of ten houses in the neighborhood. The results, in thousands of dollars, are: House County Government Private Company 216 218 349 337 295 290 236 236 236 234 271 268 256 238 276 274 311 319 224 334 a. Give a point estimate for the difference between the mean private appraisal of all such homes and the government appraisal of all such homes. b. Construct the 99% confidence interval based on these data for the difference. c. Test, at the 1% level of significance, the hypothesis that appraised values by the county government of all such houses is greater than the appraised values by the private appraisal company