55 Feminizing human faces. Research published in Nature

(August 27, 1998) revealed that people are more attracted to “feminized” faces, regardless of gender. In one experiment, 50 human subjects viewed both a Japanese female and a Caucasian male face on a computer. Using special computer graphics, each subject could morph the faces (by making them more feminine or more masculine)

until they attained the “most attractive” face. The level of feminization x (measured as a percentage) was measured.

a. For the Japanese female face, x = 10.2, and s = 31.3,. The researchers used this sample information to test the null hypothesis of a mean level of feminization equal to 0%. Verify that the test statistic is equal to 2.3.

b. Refer to part a . The researchers reported the p -value of the test as p  .02. Verify and interpret this result.

c. For the Caucasian male face, x = 15.0, and s = 25.1,.

The researchers reported the test statistic (for the test of the null hypothesis stated in part a ) as 4.23, with an associated p -value of approximately 0. Verify and interpret these results.