Please report solutions to only two decimal places. Use the updated calcium database.
- Explore the distribution of the body temperature and heart rate variables by looking at the Normality tests, Q-Q plot and histogram and describe how the distribution looks like compare to a normal distribution.
- We would like to estimate the proportion of people who smoke regularly (p = 0.48) (hint: variance for Bernoulli distribution is p(1-p)). For this, we decide to interview a sample of people from the population. If we accepted margin of error at 0.95 confidence level is 0.02,
- How many people should we interview?
- Suppose we interview a random sample of 2000 people and found that 320 of them smoke regularly. Find the 90% confidence interval for the population proportion of smokers.
- Subjects in this data are randomized into calcium treatment and placebo.
- What study design is that? And why do we need a placebo group?
- how would you design the study to better exclude the influence of age, gender and race?
- How would you design a study to examine whether calcium intake relates to cardiovascular disease in the general population? Give at least two study designs.