For Exercises 27–34, answer the following questions:

  1. Calculate .
  2. Find for a confidence interval for with 95% confidence.
  3. Construct and interpret a 95% confidence interval for .

Question 8.27

27. A random sample of with sample mean is drawn from a normal population in which .

8.1.27

(a) 2.5 (b) 1.96 (c) (70.1, 79.9). We are 95% confident that the population mean lies between 70.1 and 79.9.