The question is
Given that, x ≡ 6 (mod 11), x ≡ 13 (mod 16), x ≡ 9 (mod 21), x ≡ 19 (mod 25). Find x.
Using the Extended Euclidean Algorithm I computed the modular inverse M1^-1 = 8, M2^-1 = 15, M3^-1 = 2 and M4^-1 = 6. Now putting all the values in the formula, I get x = (a1 M1 M1^-1 + a2 M2 M2^-1 + a3 M3 M3^-1 + a4 M4 M4^-1) (mod M) = (6×8400×8 + 13×5775×15 + 9×4400×2 + 19×3696×6 ) mod (92400) = 2029869 (mod 92400) = 89469.
Am I did the correct calculation?