SUPP 5.2.The average number of days from exposure to diagnosis for a disease is 19.0 days from a sample of 1200 patients. We know that the population standard deviation is 5.5 days=.

a) Find a 95% CI for the average days from exposure to diagnosis.

b) Can we say that 95% of the values (days from exposure to diagnosis) for the sample are in the confidence interval you computed in Part a? Explain briefly.

c) Do the values for "days from exposure to diagnosis" need to be normally distributed for your Part a to be valid? Explain briefly.

d) Briefly explain the difference between.