# The University Library rare book collection has 1,300 rare

The University Library rare book collection has 1,300 rare books. In a sample of 120 books, the historical cost of each book was compared with the audited value. 10 of those books differed in their historical costs and audited values. These values are shown in the table below. Construct a 95% confidence interval estimate of the difference in the historical cost and audited value for the total population. The University Library rare book colection has 1,300 rare books. In a sample of 120 books, the historical cost of each book w