Estimating Ease of Reading Data Set 14 in Appendix B includes Flesch-Kincaid Grade Level ratings for works by Tom Clancy, J. K. Rowling, and Leo Tolstoy. If you want to estimate the mean Flesch-Kincaid Grade Level rating for pages from J. R. R.

Tolkien’s Lord of the Rings, how many pages must you randomly select if you want to be 90% confident that the sample mean is within 0.5 of the population mean? Because the samples of pages from Clancy, Rowling, and Tolstoy in Data Set 14 in Appendix B have Flesch-Kincaid Grade Level ratings with standard deviations of 2.45, 1.17, and 2.01, assume that s 5 2.45 for Lord of the Rings.