It possible because "advanced placement" courses weight grades: A:5, B:4, C:3, D:2. Ordinary classes are weighted: A:4, B:3, C:2, D:1. My son finished with a 4.33 due to AP classes. His girlfriend, the class valedictorian, had a 4.86 GPA.
Thanks for the info, I still think that is ridiculous. You should just be happy to get college credit for AP classes. I wonder when this started, I didn’t take AP classes but got dual credit from the community college during my senior year of high school, the grades did not weigh differently.