13.12 Using makeup. A study was performed in which 44 women participated as models. Each model was photographed after applying makeup as if she was going on a “night out.’’ Software was then used to create a sequence of 21 images ranging from 50% makeup to 150% makeup. Another set of observers (consisting of both sexes) was asked to look at each sequence of images and select the image that they felt was most attractive, what they felt was most attractive to other women, and what they felt was most attractive to other men. The average percent makeup over the 44 models was the response. Figure 13.8 replicates one of the plots used in their summary.8

  1. (a) Does there appear to be interaction between the sex of the observer and attractiveness category? Explain your answer.

  2. (b) Describe what you see in terms of the main effects, making sure to relate these means to 100% (the value that represents what the models applied themselves).