You can use the same reasoning as I provided on your other question (URL 24277817).
"statistical" has 11 total characters, thus 11! total permutations.
• s, a, and i each appear 2 times
• t appears 3 times
Then the number of distinguishable permutations is
11! / (2! × 2! × 2! × 3!) = 831,600
