The accompanying data file contains information on matched sample observations whose differences are normally distribu may find it useful to reference the appropriate table: ztable or ttable) Let the difference be defined as Sample 1 - Sample 2. a. Construct the 99% confidence interval for the mean difference D. (Negative value should be indicated by a minus sign final answers to 2 decimal places.) A B Sample_1 Sample_2 19112223161418172013212020161822