For Exercises 21–24, you are given matched-pair data and are asked to perform a hypothesis test. Assume that each sample of differences is obtained through dependent random sampling. Do the following:

  1. State the hypotheses.
  2. Find the critical value and state the rejection rule.
  3. Find the value of the test statistic.
  4. State the conclusion and the interpretation.

Question 14.31

23. Test whether the population mean of the differences , using level of significance .

Subject 1 2 3 4 5 6 7
Sample 1 20 25 15 10 20 30 15
Sample 2 30 30 20 20 25 35 25