For Exercises 3–14, do the following:

  1. State the hypotheses.
  2. Calculate the critical value and state the rejection rule. Also, sketch the critical region.
  3. Find the test statistic .
  4. State the conclusion and the interpretation.

Question 9.209

13. A random sample of size 36 from a population with an unknown distribution yields and . Researchers are interested in finding whether the population mean differs from 9, using level of significance .

9.4.13

(a) (b) . Reject if or if .

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(c) (d) Since is , the conclusion is reject . There is evidence at the 0.10 level of significance that the population mean differs from 9.