Final answer:
The four U.S. Presidents preceding Herbert Hoover, who are likely to be the ones referred to as presidents of ZBT, assuming it is a historically organized question, are Herbert Hoover, Calvin Coolidge, Warren G. Harding, and Woodrow Wilson.
Step-by-step explanation:
To identify the four individuals who have been president of ZBT (presumably referring to the Zeta Beta Tau fraternity, although this is not explicitly stated), we need to have historical records specific to that organization's leadership. However, based on the available lists, it seems likely that this question is actually about the Presidents of the United States. The four individuals who served as U.S. Presidents immediately before the cutoff of the list provided (Herbert Hoover) are:
- Herbert Hoover
- Calvin Coolidge
- Warren G. Harding
- Woodrow Wilson