Just 2bi please

2. Adeptly aesthetic archaeologist and adventuress Arizona Ariel assesses all antique artifacts. Because many priceless relics are booby-trapped, Ari practices estimating their weights, by Sight and by filling small canvas bags with Sand to try to equal an artifact's weight. Ari compares her Estimation Errors by both Sight and by Sandbag (1) on one set of artifacts, and then she tries again with only Sandbags (2) on a new set of relics, with the results tabulated below. ARI'S ESTIMATION ERRORS SIGHT: 3 2 2 4 4 5 6 7 8 9 SAND 1: -1 1 3 2 3 4 3 5 4 6 SAND 2: 2 1 0 0 -4 -1 -1 a. How should you interpret if Ari's Estimation Error is Negative? (5) b. Compare Ari's Weight Estimation Errors by Sight and by Sand. i. Find a 95% Confidence Interval for the Mean difference between Ari's Errors in estimating distances by Sand or Sight