Answer:
8,185,320 different leadership structures
Explanation:
Since the order at which the members of the committee are chosen matters, this is a permutation of 4 out 55 people and it is given by:
![n=(55!)/((55-4)!)=55*54*53*52 \\\\n=8,185,320](https://img.qammunity.org/2021/formulas/mathematics/college/vg357oao354a286xjqhnqb5l7tia5tntsq.png)
8,185,320 different leadership structures are possible.