Philosophical and health issues are prompting an increasing number of Taiwanese to switch to a vegetarian lifestyle. In the paper “LDL of Taiwanese Vegetarians Are Less Oxidizable than Those of Omnivores” (Journal of Nutrition, Vol. 130, pp. 1591–1596), S. Lu et al. compared the daily intake of nutrients by vegetarians and omnivores living in Taiwan. Among the nutrients considered was protein. Too little protein stunts growth and interferes with all bodily functions; too much protein puts a strain on the kidneys, can cause diarrhea and dehydration, and can leach calcium from bones and teeth. The daily protein intakes, in grams, for 51 female vegetarians and 53 female omnivores are provided on the WeissStats CD. Use the technology of your choice to do the following for each of the two sets of sample data.
a. Obtain a histogram of the data and use it to assess the (approximate) normality of the variable under consideration.
b. Obtain a normal probability plot of the data and use it to assess the (approximate) normality of the variable under consideration.
c. Compare your results in parts (a) and (b).