Answer
$5,527,200$ different leadership structures.
Work Step by Step
The order in which the members are selected matters and no member can be selected twice.
Permutation of 50 distinct members taken 4 at a time:
$_{50}P_{4}=\frac{50!}{(50-4)!}=\frac{50!}{46!}$
But, $50!=50\times49\times48\times47\times(46\times45\times44\times ... \times3\times2\times1)=50\times49\times48\times47\times46!$
$_{50}P_{4}=\frac{50\times49\times48\times47\times46!}{46!}=50\times49\times48\times47=5,527,200$
