For Exercises 17–22, we are taking a random sample from a normal population with unknown.

  1. Find .
  2. Confirm that the requirements are met for the confidence interval for .
  3. Construct the confidence interval for with the indicated confidence level.
  4. Sketch the confidence interval on a number line.

Question 8.118

21. Confidence level 95%, , ,

8.2.21

(a) (b) We are told that the population is normal. (c) (−20.6, −19.4). We are 95% confident that the population mean lies between −20.6 and −19.4.

(d)

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