A real estate company wants to evaluate two of their home appraisers for consistency in preparation for their annual state certification. It is important that different appraisers be able to give similar estimates for homes and other properties. The company selects a random sample of 10 homes in different neighborhoods around the city and independently asks each appraiser for an estimate of the home value. After they receive the estimates for each home, the company subtracts the value given by the first appraiser from the value given by the second appraiser. They create a Q-Q plot of the differences and see that the points in the plot roughly form a straight line. Are the requirements for using the desired confidence interval satisfied. a. Yes. The distribution of mean differences is normal because the sample size is large.
b. Yes. The distribution of mean differences is normal because the data have been determined to be normal.
c. No. The distribution of mean differences is not normal because the sample size is not large enough.
d. Not necessarily, because the company needs to check that the values given by each appraiser are normal, not that the differences are normal.