You are concerned about waste in the newspaper publishing process. Previously, no measurements have been taken, although it is clear that frequent mistakes often require many pounds of newsprint to be thrown away. To judge the severity of the problem and to help you decide if action is warranted, you have begun collecting data. You will take action only if the amount of waste is large enough. So far, on 27 selected mornings, the weight of wastepaper has been recorded. The average is 273.1 pounds per day, with a standard deviation of 64.2 pounds.
a. Is it appropriate for you to compute a one-sided confidence interval for this situation? Why or why not?
b. Find the most useful one-sided 99% confidence interval. Why did you choose the side you did?
c. Express your confidence interval in terms of pounds per year, assuming operations continue 365 days per year.
d. Find a one-sided 99% prediction interval for tomorrow’s waste. Compare and contrast this result to your confidence interval in part b.