The librarian at the local elementary school claims that, on average, the books in the libraryare more than 20 years old. To test thisclain,a student takes a sample of n=30 books and records the publicationdate for each. Thesample produces anaverage age of M-23.8 years with a variance of s(square)=67.5. Use this sample to conduct a one-tailed testwitha a=.01 to determine whether the average age of the library books is significantly greater than 20 years (mu >20).