#### Answer

$\frac{1}{5527200}$

#### Work Step by Step

Because the order is important, we can use the permutation rule to determine the number of possibilities: $\frac{50!}{(50-4)!}=5527200.$
We also know that $probability=\frac{number \ of \ good \ outcomes}{number\ of\ all\ outcomes}$, therefore $P=\frac{1}{5527200}$.