12.36 Analyzing contrasts. Answer the following questions for the two contrasts that you defined in the previous exercise.

  1. (a) For each contrast, give H0 and an appropriate Ha. In choosing the alternatives, you should use information given in the description of the problem, but you may not consider any impressions obtained by inspection of the sample means.

  2. (b) Find the values of the corresponding sample contrasts c1 and c2.

  3. (c) Calculate the standard errors and .

  4. (d) Give the test statistics and approximate P-values for the two significance tests. What do you conclude?

  5. (e) Compute 95% confidence intervals for the two contrasts.