12 exercise

Is u = 3. 1 using a two-tailed test with a b. Is the estimate from the participants significantly higher than the actual number (u = 3.1)? Use a one-tailed test with a = .05. 12. The librarian at the local elementary school claims that, on average, the books in the library are more than 20 years old. To test this claim, a student takes a sample of n = 30 books and records the publication date for each. The sample produces an average age of M = 23.8 years with a variance of s = 67.5. Use this sample to conduct a one-tailed test with a = .01 to determine whether the average age of the library books is significantly greater than 20 years (H > 20). 13. Standardized measures seem to indicate that the average level of anxiety has increased gradually over