Gerald, a high school senior, sees another student stumble and drop her books in the hall. if gerald makes the fundamental attribution error, how would he most likely explain the student's behavior?

He would most likely believe that She is a clumsy person.
a fundamental attribution error happens when someone attriuting a certain situation based on the interpretation of their own behavior rather than considering other existing factor.
In this particular case, Gerald fail to consider some other factors such as that girl could've been walking on slippery floor, or she's being pushed before Gerald saw her.