For Exercises 23–28, we are taking a random sample from a population with unknown. However, do not assume that the population is normally distributed.

  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 8.120

23. Confidence level 90%, sample size 256, sample mean 100, sample standard deviation 16.

8.2.23

(a) (b) We are not told that the population is normal. However, the sample size is large ( is ). (c) (98.3, 101.7). We are 90% confident that the population mean lies between 98.3 and 101.7.

(d)

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