12.35 Writing contrasts, continued. Return to the eye study described in Example 12.15 (page 663). Let μ1, μ2, μ3, and μ4 represent the mean scores for blue, brown, gaze down, and green eyes, respectively.
(a) Because a majority of the population in this study are Hispanic (eye color predominantly brown), we want to compare the average score of the brown eyes with the average of the other two eye colors. Write a contrast that expresses this comparison.
(b) Write a contrast to compare the average score when the model is looking at you versus the score when looking down.