How much time do Americans spend eating or drinking? Suppose for a random sample of 1001 Americans age 15 or older, the mean amount of time spent eating or drinking per day is 1.22 hours with a standard deviation of 0.65 hours?
a. A histogram of time spent eating & drinking each day is skewed right. Use this result to explain why a large sample size is needed to construct a confidence interval for the mean time spent eating & drinking each day.
b. In 2010, there were over 200 million Americans age 15 or older. Explain why this, along with the fact that the data were obtained using a random sample, satisfies the requirements for constructing a confidence interval.
c. Determine & interpret a 95% confidence interval for the mean amount of time Americans age 15 or older spend eating & drinking each day.
d. Could the interval be used to estimate the mean amount of time a 9-year-old American spends eating & drinking each day. Explain.