Research results indicate that physically attractive people are also perceived as being more intelligent (Eagly, Ashmore, Makhijani, & Longo, 1991). As a demonstration of this phenomenon, a researcher obtained a set of 10 photographs, = showing men who were judged to be attractive and = showing men who were judged to be unattractive. The photographs were shown to a sample of n = 25 college students and the students were asked to rate the intelligence of the person in the photo on a scale from 1 to 10.
For each student, the researcher determined the average rating for the = attractive photos and the average for the = unattractive photos, and then computed the difference between the two scores. For the entire sample, the average difference was MD = 2.7 (attractive photos rated higher) with σ = 2.00.
Are the data sufficient to conclude that there was a significant difference in perceived intelligence for the two sets of photos? Use a two-tailed test at the .05 level of significance.