Data 2.11 on page 111 describes a dataset that gives nutrient levels in people’s blood as well as information about their eating habits. We use the people for whom information is available as a sample from the population of all people. Use technology and the data stored in the file NutritionStudy to answer the following questions. Justify your answers to the questions using specific values from the statistical software package that you use. In particular, for all tests, give the null and alternative hypotheses, the pvalue from the computer output, and the conclusion in context.

(a) Find and interpret a 95% confidence interval for the percent of people that smoke.

(b) Find and interpret a 99% confidence interval for the average number of grams of fiber per day that people eat. Give the best estimate, the margin of error, and the confidence interval.

(c) Find and interpret a 90% confidence interval for the average number of grams of fat per day that people eat.

(d) Is there evidence of a difference in the percent of current smokers by gender?

(e) Is there evidence of a difference in the mean cholesterol level of males and females?

(f) Is there evidence of a difference in mean level of beta carotene in the blood (BetaPlasma) between smokers and non-smokers?  

Data 2.11 on page 111

In a study on the association between diet and levels of retinol and beta-carotene in the blood stream, researchers recorded a variety of dietary and demographic variables for the subjects. Variables include alcohol consumption, average daily calories, age, gender, multivitamin use, fat grams per day, fiber grams per day, smoking habits, etc. The data are available in NutritionStudy.