... ’ ’ ¯ ´ P (0 ≤ X ≤ 2) = P0 + P1 + P2 P0 = P (X = 0) = 20 2 e 0! P1 = P (X = 1) = 21 2 e 1! P2 = P (X = 2) = 22 2 e 2! Do d´ P (0 ≤ X ≤ 2) = (1 + + 2) e 2 = 5 (2, 71) 2 = 0, 6808 ¯o ´ ´ ˜ Chuong ... phˆi x´c suˆt sau ı ım y a e o ’ a o a a X P 10 11 12 12 12 12 12 12 12 Ta c´ o 2 1 E(X) = 12 + 12 + 12 + 12 + 12 + 10 12 + 11 12 = 93 12 = 31 = 7, 75 ˜ • V´ du Cho X l` dai luong ngˆu nhiˆn ... = x2 (4 − x)dx = a) k = 4, b) F (x) = 13 25 6 ´ − e−2x (2x2 + 2x + 1) nˆu x > e ´ nˆu x < e c) mod(X) = 1, d) E(X) = , V ar(X) = X ∈ B (25 0, 2% ) a) P (X = 2) = 0, 08 42, b) P (x ≤ 2) = 0, 124 7...