to a les ea su pi 12.35 Writing contrasts, continued. Return to the eye study described in Example 12.15 (page 663). Let ui, P2, H3, and My 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. be seen. This picture was used in three tarret ads. The only de the models eves, which were made to be either brown, blue ward so the eyes are not visible. A total of 222 surveys were used to w second pictures the model is in virtually the same pose but loc Outputs from Excel SAS, and Minitab are given in Figure 12.9 In one picture, the Excel Excel, SAS ut for the Example 12.15 D 8 Anos Single Factor Count 67 SUMMARY Groupe Blue Brown Down Green Sum Average Variance 214 3.19403 1.079055 1378 3724334 2.542447 127.4 3.107317 2.326695 3.859742775332 FIG 41 77 MS 10 ANOVA Source of Variation 12 Between Groups Within Groups 14 SS 2441966 613.1357 For 18.139886 2894117 00361842 218 2.612563 537 5584 221 SAS The GLM Procedure Dependent Variable score 2.390.00 Source DF Sum of Squares Mean Square Madel 24.4196586 3.1396862 218 613.1387197 2.8125620 Corrected Total 221 637 5583734 R-Square Coeff Var Root MUSE Score Mean 0.03830247.95331 1.677070 3.497297 I Love of Group Score N Mean Std D 673.19402985 1.75472355 Blue Brown 372.72432432 1.71535636 Down 41 3.10731707 1.52535082 Green 77 3.85974026 1.66593262 al Minitab One way ANOVA: Score versus Group Sourc DF Group Total 221 637.56 1.677 R-3.833 arown Pooled st DV 1.62 There is evidence at the 5% significance level to reject the null hype s that the four groups have equal means (P = 0.036). In Exercises 12 2 12.36 (page 686), you are asked to perform further inferences trasts. YOND THE BASICS sting the Equality of Spread ile the standard deviation is a natural measure of spread for Normal herause skewe