For Exercises 15–26, do the following:

  1. State the hypotheses and the rejection rule using the -value method.
  2. Calculate the test statistic .
  3. Find the -value. (Use technology or estimate the -value.)
  4. State the conclusion and the interpretation.

Question 9.216

20. A random sample of size 100 from a population with an unknown distribution yields and . Researchers are interested in finding whether the population mean is less than 28, using level of significance .