Suppose an allergist can explain why children in his clinic approximate a random sample of all American children. Based on the sample of his clinic's pediatric patients, he calculates a 95% confidence interval for the mean age at which children in the U.S. are diagnosed with a peanut food allergy be 11 to 15 months old.

1.)What is the mean age of diagnosis for children in his practice? What is the margin of error?

a.We need to know the sample size and either x or in order to answer the question.

b.The mean can't be determined from the given information, but the margin of error is 4 months.

c.The mean is 13 months and the margin of error is 2 months.

d.The mean is 13 months and the margin of error is 4 months.

2.)Two of the following are correct interpretations of the doctor's confidence interval. Identify them.

a.There is a 95% chance that the mean age at diagnosis is between 11 and 15 months

b.We are 95% confident the mean age of all diagnoses is somewhere between 11 and 15 months.

c.If we repeated this sampling many times, 95% of the sample means would fall between 11 and 15

d.If we could repeat such sampling for all possible sample of the same size, 95% of the confidence intervals we'd construct would contain the true, but unknown and fixed population mean.

e.95% of all children are diagnosed between the ages of 11 and 15 months