Weighted GPA at Harvard?

Colleges and Universities A-Z Harvard University
1

I looked online and saw that the average GPA at Harvard is a 4.04 on a 4.0 scale. How can the unweighted GPA be above a 4.0? Else, what is the average weighted and unweighted GPA?

2

4.3 =A+

3

This question has been asked many times before, e.g.:
http://talk.qa.collegeconfidential.com/harvard-university/1995733-how-are-harvard-students-average-hs-gpas-above-4-0.html