Chapter 11.1, Problem 4E

Use the information in the previous exercise to answer the following questions.

1. a. Construct a 90% confidence interval estimate of the difference in mean Flesch reading ease score for health-related pages on Wikipedia and health-related pages on WebMD.
2. b. What does this confidence interval imply about the readability of health-related information from these two sources? Is this consistent with the conclusion in the hypothesis test of the previous exercise?

Many people now tum to the Internet to get information on health-related topics. The paper “An Examination of Health, Medical and Nutritional Information on the Internet: A Comparative Study of Wikipedia, WebMD and the Mayo Clinic Websites” (The International Journal of Communication and Health [2015]: 30–38) used Flesch reading ease scores (a measure of reading difficulty based on factors such as sentence length and number of syllables in the words used) to score pages on Wikipedia and on WebMD. Higher Flesch scores correspond to more difficult reading levels. The paper reported that for a representative sample of health-related pages on Wikipedia, the mean Flesch score was 26.7 and the standard deviation of the Flesch scores was 14.1. For a representative sample of pages from WebMD, the mean score was 43.9 and the standard deviation was 19.4. Suppose that these means and standard deviations were based on samples of 40 pages from each site. Is there convincing evidence that the mean reading level for health-related pages differs for Wikipedia and WebMD? Test the relevant hypotheses using a significance level of 0.05.