A study was conducted to determine if there was a difference in humor content in British and American trade magazine advertisements. In an independent random sample of 270 American trade magazine advertisements, 56 were humorous. An independent random sample of 203 British trade magazine advertisements contained 52 humorous ads. Do these data provide evidence that there is a difference in the proportion of humorous ads in British versus American trade magazines?
Nutrition Research-Based Exercises
A large research study conducted by the Economic Research Service (ERS), a prestige think tank research center in the U.S. Department of Agriculture is conducting a series of research studies to determine the nutrition characteristics of people in the United States. This research is used for both nutrition education and government policy designed to improve personal health.
The U.S. Department of Agriculture (USDA) developed the Healthy Eating Index (HEI) to monitor the diet quality of the U.S. population, particularly how well it conforms to dietary guidance. The HEI-2005 measures how well the population follows the recommendations of the 2005 Dietary Guidelines for Americans. In particular, it measures, on a 100-point scale, the adequacy of consumption of vegetables, fruits, grains, milk, meat and beans, and liquid oils. Full credit for these groups is given only when the consumer consumes some whole fruit, vegetables from the dark green, orange, and legume subgroup, and whole grains. In addition the HEI-2005 measures how well the U.S. population limits consumption of saturated fat, sodium, and extra calories from solid fats, added sugars, and alcoholic beverages. You will use the Total HEI-2005 score as the measure of the quality of a diet. Further background on the HEI and important research on nutrition can be found at the government Web sites indicated at the end of this case-study document. A healthy diet results from a combination of appropriate food choices, which are strongly influenced by a number of behavioral, cultural, societal, and health conditions. We cannot simply tell people to drink orange juice, purchase all food from organic farms, or take some new miracle drug. Research and experience have developed considerable knowledge, and if we, for example, follow the diet guidelines associated with the food pyramid, we will be healthier. It is also important that we know more about the characteristics that lead to healthier diets so that better recommendations and policies can be developed. And, of course, better diets will lead to a higher quality of life and lowered medical-care costs. In the following exercises you will apply your understanding of statistical analysis to perform analysis similar to that done by professional researchers.
The data file HEI Cost Data Variable Subset contains considerable information on randomly selected individuals who participated in an extended interview and medical examination. There are two observations for each person in the study. The first observation, identified by daycode = 1, contains data from the first interview, and the second observation, daycode = 2, contains data from the second interview. This data file contains the data for the following exercises. The variables are described in the data dictionary in the Chapter 10 appendix.