R. Reifen et al. studied various nutritional measures of Ethiopian school children and published their findings in the paper "Ethiopian-Born and Native Israeli School Children Have Different Growth Patterns" (Nutrition, Vol. 19, pp. 427-431). The study, conducted in Azezo, North West Ethiopia, found that malnutrition is prevalent in primary and secondary school children because of economic poverty.
The weights, in kilograms (kg), of 60 randomly selected male Ethiopian-born school children of ages 12-15 years are presented on the WeissStats CD. Use the technology of your choice to do the following.
a. Obtain a normal probability plot, boxplot, histogram, and stem-and-leaf diagram of the data.
b. Based on your results from part (a), can you reasonably apply the z-interval procedure to the data? Explain your reasoning.
c. Find and interpret a 95% confidence interval for the mean weight of all male Ethiopian-born school children of ages 12- 15 years. Assume that the population standard deviation is 4.5 kg.