12. A recent report indicates that physically attractive people are also perceived as being more intelligent. As a demonstration of this phenomenon, a researcher obtained a set of 10 photos, 5 showing men who were judged to be attractive and 5 showing men who were judged to be unattractive. The photos 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 5 attractive photos, and the average for the 5 unattractive photos, and then computed the difference between the two scores. For the entire sample, the average difference was Md=2.7 (attractive photo rated higher) with s =2.0. 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.
The solution provides two-tailed test at the .05 level of significance.